---

In-Depth Reports Home

In This Report

	Highlights
	Introduction
	Diagnosis
	Causes
	Risk Factors
	Complications
	Symptoms
	Treatment
	Lifestyle Changes
	Classes of Medications
	Resources
	References

Related Reports

	Coronary artery disease
	Heart attack and acute coro...
	Heart failure
	Cholesterol
	Exercise
	Stress
	Smoking
	Heart-healthy diet
	Stroke
	Weight control and diet

Encyclopedia

	High blood pressure (Hypert...
	Essential hypertension
	Malignant hypertension

More Features

Printer-friendly version

High blood pressure

Highlights

Drug Approval

In December 2007, the U.S. Food and Drug Administration approved nebivolol (Bystolic), a new beta blocker drug. Beta blockers are usually used to treat high blood pressure in combination with other types of medicine such as diuretics and ACE inhibitors.

Blood Pressure Screening Guidelines

Current guidelines from the U.S. Preventive Services Task Force recommend that all adults age 18 years and older have their blood pressure measured.

High Blood Pressure (Hypertension) in Children

Rates of hypertension and pre-hypertension are increasing among children and adolescents, according to a survey published in 2007 in Circulation. Another 2007 study, published in the Journal of the American Medical Association, suggests that pediatric high blood pressure is underdiagnosed. Researchers found that a diagnosis of hypertension was missed in about 75% of children with elevated blood pressure readings. Many doctors believe that increasing rates of childhood obesity are contributing to the rise in pediatric hypertension.

Pre-Eclampsia and Heart Disease

Women with heart disease risk factors (such as high blood pressure and unhealthy cholesterol levels) have a greater risk of developing pre-eclampsia, and women who have had pre-eclampsia are at increased risk for later heart disease, indicate several studies in the November 2007 issue of the British Medical Journal. High blood pressure is a component of pre-eclampsia, a potentially dangerous condition that can occur during the last trimester of pregnancy.

Introduction

High blood pressure, also called hypertension, is elevated pressure of the blood in the arteries. Hypertension results from two major factors, which can be present independently or together:

• The heart pumps blood with excessive force.
• The body's smaller blood vessels (known as the arterioles) narrow, so that blood flow exerts more pressure against the vessels' walls.

Blood pressure is the force applied against the walls of the arteries as the heart pumps blood through the body. The pressure is determined by the force and amount of blood pumped and the size and flexibility of the arteries.

Although the body can tolerate increased blood pressure for months and even years, eventually the heart may enlarge (a condition called hypertrophy), which is a major factor in heart failure.

Click the icon to see an image of hypertrophic cardiomyopathy.

Such pressure can also injure blood vessels in the heart, kidneys, the brain, and the eyes.

Two numbers are used to describe blood pressure: the systolic pressure (the higher and first number) and the diastolic pressure (the lower and second number). Health dangers from blood pressure may vary among different age groups and depending on whether systolic or diastolic pressure (or both) is elevated. A third measurement, pulse pressure, may also be important as an indicator of severity.

Blood pressure is measured in millimeters of mercury (mm Hg). According to current adult guidelines, blood pressure is categorized as normal, prehypertensive, and hypertensive (which is further divided into Stage 1 and 2, according to severity). People in normal health should have a blood pressure reading of 120/80 mm Hg or less. High blood pressure is generally considered to be a blood pressure reading greater than or equal to 140 mm Hg (systolic) or greater than or equal to 90 mm Hg (diastolic). Blood pressure readings in the prehypertension category (120 -139 systolic or 80 - 89 diastolic) indicate an increased risk for developing hypertension.

Current guidelines for children are based on percentile ranges for a childs body size. Hypertension is defined as average systolic and diastolic readings that are greater than the 95th percentile for gender, age, and height on at least three occasions. Pre-hypertension in children is diagnosed when average systolic or diastolic blood pressure levels are at least in the 90th percentile but less than the 95th percentile. For adolescents, as with adults, blood pressure readings greater than 120/80 are considered prehypertensive. Increasing rates of childhood obesity have led to increasing rates of hypertension and pre-hypertension among children and adolescents. Although more children are having high blood pressure, recent studies indicate that pediatric hypertension is frequently underdiagnosed.

Systolic Blood Pressure. The systolic pressure (the first and higher number) is the force that blood exerts on the artery walls as the heart contracts to pump out the blood. High systolic pressure is now known to be a greater risk factor than diastolic pressure for heart, kidney, and circulatory complications and for death, particularly in middle-aged and elderly adults. The wider the spread between the systolic and diastolic measurements, the greater the danger.

Diastolic Blood Pressure. The diastolic pressure (the second and lower number) is the measurement of force as the heart relaxes to allow the blood to flow into the heart. High diastolic pressure is a strong predictor of heart attack and stroke in young adults.

Pulse Pressure. Pulse pressure is the difference between the systolic and the diastolic readings. It appears to be an indicator of stiffness and inflammation in the blood-vessel walls. The greater the difference between systolic and diastolic numbers, the stiffer and more injured the vessels are thought to be. Although not yet used by doctors to determine treatment, evidence suggests that it may prove to be a strong predictor of heart problems, particularly in older adults. Some studies suggest that in people over 45 years old, every 10 mm Hg increase in pulse pressure increases the risk for stroke rises by 11%, cardiovascular disease by 10%, and overall mortality by 16%. (In younger adults the risks are even higher.)

Click the icon to see an animation about blood pressure.

Hypertension Categories

There are a number of ways to categorize or describe hypertension. Some experts categorize hypertension into the following types:

• Essential Hypertension. Essential hypertension is also known as primary or idiopathic hypertension. About 90% of all high blood pressure cases are this type. The causes of essential hypertension are unknown but are based on complex processes in all major organs and systems, including the heart, blood vessels, nerves, hormones, and the kidneys.
• Secondary Hypertension. Secondary hypertension comprises about 5% of high blood pressure cases. In this condition, the cause has been identified.

Other doctors categorize hypertension based on what portion of the blood pressure reading is abnormal:

• Isolated Systolic Hypertension. Elevated systolic pressure may pose a significant danger for heart problems and stroke even when diastolic is normal -- a condition called isolated systolic hypertension. This occurs when systolic hypertension is over 140 mm Hg but diastolic pressure is normal. It is related to arteriosclerosis (hardening of the arteries). Isolated systolic hypertension is the most common form of hypertension in people older than age 50. In one study, it comprised 87% of hypertension cases in people ages 50 - 59

Click the icon to see an image of atherosclerosis.

• Diastolic Hypertension. Diastolic hypertension refers to an elevated diastolic blood pressure reading. This subtype is most common in middle-aged adults age 30 - 50. Most cases of essential hypertension fall into this group.
• White Coat Hypertension. This is an elevated blood pressure reading that occurs only during a visit to the doctor's office, but not at home. It is defined as a daytime blood pressure away from the doctor's office of less than 135/85 mg Hg and no evidence of complications of blood pressure elsewhere in the body. It is a factor in about 20% of patients with findings of mild hypertension during office visits. Although previously considered a relatively harmless condition, some research now suggests that white-coat hypertension may carry some long-term risks for stroke or future heart problems.

Diagnosis

Most physical exams include a blood pressure measurement. Patients should not smoke or drink caffeinated beverages within 30 minutes before their blood pressure measurement.

The Sphygmomanometer

• The standard instrument used to measure blood pressure is called a mercury sphygmomanometer. Measurements are given as units of mercury, which has filled the central column in standard sphygmomanometers for years. (Some people view the mercury sphygmomanometer as an environmental health hazard, but modern devices are designed to prevent mercury spillage.)
• An inflatable cuff with a meter attached is placed around the patient's arm over the artery while the patient is seated, their back is supported, and the arm being used is around the level of the heart. The inflated cuff briefly interrupts the flow of blood in the artery, which then resumes as the cuff is slowly deflated.
• The person taking the blood pressure listens through a stethoscope for so-called Korotkoff sounds, which first appear as blood begins to flow through the artery as the cuff is deflated and then change in tone and volume.
• The first pumping sound your health care provider hears is recorded as the systolic pressure, and the last sound is the diastolic pressure.
• If a first blood pressure reading is above normal, the health professional may take two or more measurements separated by 2 minutes with the patient sitting or lying down. Another measurement may be taken after the patient has been standing for 2 minutes. If the measurements are still elevated, your health care provider should take blood pressure readings from both arms.

To measure blood pressure, your doctor uses an instrument called a "sphygmomanometer," more often referred to as a blood pressure cuff. The cuff is wrapped around your upper arm and inflated to stop the flow of blood in your artery. As the cuff is slowly deflated, your doctor uses a stethoscope to listen to the blood pumping through the artery. These pumping sounds register on a gauge attached to the cuff. The first pumping sound your doctor hears is recorded as the systolic pressure, and the last sound is the diastolic pressure.

Although this test has been used for more than 90 years, it is not completely accurate or sensitive. The following factors can cause a falsely low pressure reading:

• An arm cuff that is too wide
• Recent exercise
• Not smoking for a while after heavy, long-term smoking

Falsely high pressure can result from:

• An arm cuff that is too small
• Talking during the test
• Recently consuming foods or beverages (such as coffee) that raise blood pressure

Office blood pressure readings taken by a doctor are more likely to be higher than readings measured at home. This so-called white-coat hypertension requires additional readings by a nurse or by the patient. Home monitoring improves the accuracy of a simple office measurement. An average of all the measurements will be considered in the diagnosis of hypertension. If high normal or high blood pressure persists, further tests should be performed to determine if the organs are affected.

Home Monitoring

Monitoring Equipment. A number of methods are available for checking blood pressure between doctor visits. Evaluating blood-pressure outside of the doctor's office is useful for people who experience wide blood pressure swings, such as those who have white-coat hypertension or show poor response to drug therapy. For some patients, accurately measuring blood pressure at home over a full day can be a significantly better predictor of cardiovascular risk than standard office-based measurements.

• Devices are available that allow 24-hour ambulatory blood pressure monitoring and electronically store results for analysis by the doctor. It is not clear if their added benefits justify their expense, however.
• Manual cuffs with a sphygmomanometer and a stethoscope are fairly accurate. The far majority of people can be trained to use these correctly. The cuff must be the right size (one size does not fit all). Devices that use a digital readout and a cuff that can be electronically inflated and deflated are available, but are not always well standardized and may underestimate blood pressure.

Blood Pressure Variations at Home. In general, everyone's blood pressure varies in the same way throughout a given day. In monitoring at home, it is important to note these changes:

• Blood pressure is usually highest at work.
• It drops slightly at home.
• It then normally dips to its lowest level during sleep. There are important exceptions. Certain people have a condition called nondipper hypertension, in which blood pressure does not fall at night. Postmenopausal women appear to be at particular risk for this phenomenon, and it may pose a special danger for heart disease and stroke (particularly in older African-American women). It has also been linked to salt-sensitivity and insulin resistance.

Click the icon to see an image of stroke.

• Upon waking, pressure in most people typically increases suddenly. In people with severe high blood pressure, this is the highest risk period for heart attack and stroke.

Click the icon to see an image of a heart attack.

Some studies have reported that when patients record and report their own blood pressure, they are unreliable and don't always tell the truth. Despite the difficulties and controversy surrounding this issue, home blood pressure monitoring has been shown to encourage patients to use measures that control their blood pressure and thereby reduce the risk of cardiovascular events.

Click the icon to see an image about monitoring blood pressure.

Physical Examination for Complications of Hypertension

If blood pressure is elevated, the doctor will check the patient's pulse rate, examine the neck for distended veins or an enlarged thyroid gland, check the heart for enlargement and murmurs, and examine the abdomen and the eyes.

Click the icon to see an image of the thyroid gland.

Medical History

If hypertension is suspected, the doctor should obtain the following information:

• A family and personal medical history, especially incidence of high blood pressure, stroke, heart problems, kidney disease, or diabetes.
• Risk factors for heart disease and stroke, including tobacco use, salt intake, obesity, physical inactivity, and unhealthy cholesterol levels.
• Any medications being taken.
• Any symptom that might indicate so-called secondary hypertension (that is, caused by another disorder). Such symptoms include headache, heart palpitations, excessive sweating, muscle cramps or weakness, or excessive urination.
• Any emotional or environmental factors that could affect blood pressure.

Laboratory and Other Tests

If a physical examination indicates hypertension, additional tests may help determine whether it is secondary hypertension or essential hypertension (no other disorder is present) and whether organ damage is present.

Blood Tests and Urinalysis. These tests are performed to check for a number of factors, including potassium levels, cholesterol, blood sugar, infection, kidney function, and other possible problems. Measuring blood levels of the protein creatinine, for example, is important for all hypertensive patients in order to determine kidney damage. Patients suspected of having problems involving the adrenal glands may have several tests.

Tests to Evaluate the Heart. These tests include:

• An electrocardiogram (ECG) is performed on most patients in the doctor's office.

Click the icon to see an image of an electrocardiogram.

• An exercise stress test may be needed for patients who also have symptoms of coronary artery disease.
• An echocardiogram is needed when it would help the doctor decide whether to start treatment. Most of the time this test is not necessary for patients who have only hypertension and no other symptoms.

Click the icon to see an image of blood pressure tests.

Tests To Evaluate the Kidneys. These tests include:

• A Doppler or duplex test may be performed to see whether one of the arteries supplying blood to the kidney is narrowed, a condition called renal artery stenosis.
• An ultrasound may also be performed to examine the kidneys.

Causes

Hypertension is referred to as essential (primary) when the doctor is unable to identify a specific cause. It is by far the most common type of high blood pressure. The causes of this type, while unknown, are likely to be a complex combination of genetic, environmental, and other factors.

Genetic Factors. A number of genetic factors or interactions between genes play a major role in essential hypertension. Experts think that the chromosomes (13 and 18) house the genes responsible for blood pressure regulation, although pinning down the range of specific genes involved in hypertension is more difficult.

• Genes under intense study are those that regulate a group of hormones known collectively as the angiotensin-renin-aldosterone system. This system influences all aspects of blood pressure control, including blood vessel contraction, sodium and water balance, and cell development in the heart.
• Studies suggest that some people with essential hypertension may inherit abnormalities of the sympathetic nervous system. This is the part of the autonomic nervous system that controls heart rate, blood pressure, and the diameter of the blood vessels.

Insulin Resistance and Type 2 Diabetes. Hypertension is strongly associated with diabetes, both type 1 and type 2. Kidney damage is generally the cause of high blood pressure in type 1 diabetes. Obesity and insulin resistance are the factors associated with hypertension in type 2 diabetes, the more common type. People with type 2 diabetes generally have normal or high levels of insulin, a critical hormone in the metabolism of sugar. However, they are unable to use the insulin, a condition called insulin resistance. Without insulin, blood glucose (sugar) levels rise, the hallmark of diabetes.

People who have insulin resistance or full-blown diabetes plus hypertension have a significantly greater chance for heart attack, kidney disease, and stroke than people who have only high blood pressure.

Obesity. Obesity on its own has a number of possible effects that could lead to hypertension. It may blunt certain actions of insulin that open blood vessels, and it may cause structural changes in the kidney and abnormal handling of sodium. It is also associated with alterations in the systems that regulate blood flow.

Kidney Disease. Kidney disease is the most common cause of secondary hypertension, particularly in older people.

Coarctation of the Aorta. Narrowing of the aorta soon after it leaves the heart can cause high blood pressure, which often shows up in one of the arms.

Other Medical Conditions. Adrenal tumors, pheochromocytoma, and Cushing syndrome can all present with hypertension.

Medications. Certain prescription and over-the-counter drugs can cause temporary high blood pressure. They include:

• Corticosteroids when given by mouth or intravenously
• Nonsteroidal anti-inflammatory drugs (NSAIDs) -- such as ibuprofen (Motrin), naproxen (Aleve), and aspirin -- may cause secondary hypertension as well as other complications. In one important study, women who used an NSAID for 5 or more days a month had a significantly higher risk for hypertension. The more often they used these drugs, the higher the risk. A 2007 study indicated that NSAIDs also increase the risk for hypertension in men. A 2005 study found that NSAIDs increase the risk for kidney failure, and that the risk is significantly greater for all patients with hypertension. Patients who took diuretics along with NSAIDs had 11.6 times the risk of developing acute kidney failure compared to non-NSAID users. The relative risk for calcium channel blockers and NSAIDs was 7.8. The researchers advised that patients with hypertension or heart failure should use NSAIDs with caution.
• Cold medicines containing pseudoephedrine have also been found to increase blood pressure in hypertensive people, although they appear to pose no danger for those with normal blood pressure.
• Oral contraceptives ("the pill") increase the risk for high blood pressure, particularly in women who are older than 35 years, obese, smokers, have strong family history of hypertension, or some combination. Stopping the pill nearly always reduces blood pressure.

Alcohol.An estimated 10% of hypertension cases are caused by alcohol abuse (three or more alcohol drinks a day), with heavier drinkers having higher blood pressure. Women may be more sensitive than men to the blood pressure effects of alcohol. Moderate drinking (one or two drinks a day) has benefits for the heart and may even protect against some types of stroke. In particular, red wine may have chemicals that help blood pressure.

Risk Factors

During the last decade, the number of Americans with high blood pressure has increased by 30%. Over 65 million American adults now have high blood pressure, and this condition affects close to 1 billion people worldwide. Less than half of these people are on medication, however, and only about half of this group have their blood pressure under good control with such drugs. Older people are less likely to be treated adequately. The majority of people with high blood pressure have the mild type, but even this condition requires attention.

Age and Gender

Age is the major risk factor of hypertension. Blood pressure increases with age in both men and women, and, in fact, the lifetime risk for hypertension is nearly 90%. Two-thirds of Americans over age 60 have hypertension. Older women (60 years and above) currently have the highest rates of hypertension, and mortality rates from hypertension are higher in women than in men. Hypertension is also becoming more common in children and teenagers.

Ethnicity

Compared to Caucasians, Americans are much more likely to die of stroke, heart disease, and end-stage kidney disease. In general, about a third of African-American men and women have hypertension; it may account for over 40% of all deaths in this group. High blood pressure tends to start at a younger age among African-Americans, is often more severe, and causes greater target organ damage.

The rates of hypertension in Hispanic Americans, Caucasians, and Native Americans are similar and are lower than in African-Americans. The rate is much lower in Asian/Pacific Islanders. However, nearly 75% of older Japanese American men are hypertensive.

A number of theories have addressed the reasons for this difference. It may have to do with levels of, or different response to, various body proteins involved in the control of blood pressure. Social and income disparities and dietary issues may also explain many of the differences in blood pressure rates observed between ethnic groups. For example, while African-Americans have a disproportionately high rate of hypertension, one study in rural African villages, where diets are rich in fish, reported only a 3% rate of high blood pressure among inhabitants.

In any case, hypertension appears to be dangerously undertreated in major minority groups. Inadequately controlled hypertension is the major factor for the higher mortality rate from heart disease among African-Americans, and special treatment considerations need to be addressed in this population. African-Americans often need at least two medications to help lower their blood pressure.

Obesity

About one-third of patients with high blood pressure are overweight. Even moderately obese adults have double the risk of hypertension than people with normal weights. Moreover, the increase in blood pressure in aging Americans may be due primarily to weight gain. (In other cultures old age does not necessarily coincide with weight gain or high blood pressure.) Children and adolescents who are obese are at greater risk for high blood pressure when they reach adulthood.

Interestingly, thin people with hypertension are at higher risk for heart attacks and stroke than obese people with high blood pressure. Experts think that thin people with hypertension are likely to have conditions that pose greater dangers to health, such as an enlarged heart or stiff arteries that cause the blood pressure to rise.

Tobacco Usage

Smoking is a major risk factor. One study reported that smokers have blood pressures up to 10 points higher than nonsmokers. Also, since smokers generally have their blood pressure measured at times when they have not been smoking, it is possible that their blood pressure normally runs higher than when measured at a doctor's office.

Low Birth Weight

Low birth weight, particularly in girls, has been associated with high blood pressure in both childhood and adulthood. One study suggested that breastfeeding these babies may help reduce this risk. Another study reported high levels of stress hormones in babies with low birth weight, which could increase the risk for high blood pressure later on. Low birth weight is also associated with subsequent obesity, a major contributor to hypertension.

Diabetes

Up to 75% of cardiovascular problems in people with diabetes may be due to hypertension. There are strong biologic links between insulin resistance (with or without diabetes) and hypertension. It is unclear which condition causes the other. Some experts believe angiotensin may be the common factor linking diabetes and high blood pressure. This natural chemical not only influences all aspects of blood pressure control but also interferes with insulin's normal metabolic signaling. People with diabetes or chronic kidney disease need to reduce their blood pressure to 130/80 mm Hg or lower to protect the heart and help prevent other complications common to both diseases. Lowering systolic pressure may be particularly important for people with diabetes.

Emotional Factors

People who are anxious or depressed may have over twice the risk for high blood pressure than those without these problems.

Mental Stress/Anxiety. Recent evidence confirms the association between stress and hypertension. In one 20-year study, men who periodically measured highest on the stress scale were twice as likely to have high blood pressure as those with normal stress. The effects of stress on blood pressure in women were less clear. Job stress and lack of career success have been specifically linked to high blood pressure in both men and women.

Depression. Mounting evidence suggests that depression has physiological effects that impair the heart and contribute to destructive behaviors, such as weight gain, smoking, or alcohol abuse. Those who score highest for depression often have up to twice the risk of high blood pressure.

Obstructive Sleep Apnea

Obstructive sleep apnea, a disorder in which breathing halts briefly but repeatedly during sleep, is present in many patients with hypertension. The relationship between sleep apnea and hypertension has been thought to be largely due to obesity, but studies are finding a higher rate of hypertension in people with sleep apnea regardless of their weight. The use of a device known as nasal continuous positive airway pressure (CPAP) to treat patients with both sleep apnea and hypertension has been found to have only a small benefit for high blood pressure.

Time and Seasonal Factors

Blood pressure levels tend to be lowest during the morning and midday hours and highest at the end of the day. Seasonal changes also affect blood pressure, with hypertension increasing during cold months and declining during the summer. Blood pressure readings can vary by as much as 40%, depending on the time of day and season.

Complications

Hypertension places stress on several organs (called target organs), including the kidneys, eyes, and heart, causing them to deteriorate over time. High blood pressure contributes to 75% of all strokes and heart attacks. It is particularly deadly in African-Americans.

Risk of complications or rapid progression of hypertension become more likely in the presence of other risk factors, including significant elevation of blood pressure, increasing age (men over age 55 and women over age 65), smokers, abnormal cholesterol, family history of premature heart disease, obesity, diabetes, coronary artery disease, and other evidence of vascular disease.

Hypertension is a disorder characterized by chronically high blood pressure. It must be monitored, treated and controlled by medication, lifestyle changes, or a combination of both.

Emergency Conditions

Malignant hypertension, an emergency condition resulting from untreated primary hypertension, can be lethal. Most patients have significant elevation of their blood pressure and symptoms of acute heart, cerebrovascular, or kidney involvement.

Stroke

About two-thirds of people who suffer a first stroke have moderate elevated blood pressure (160/95 mm Hg or above). Hypertensive people have up to 10 times the normal risk of stroke, depending on the severity of the blood pressure in the presence of other risk factors. Hypertension is also an important cause of so-called silent cerebral infarcts, or blockages, in the blood vessels in the brain (mini-strokes) that may predict major stroke or progress to dementia over time.

Alzheimer's Dementia

Isolated systolic hypertension may pose a particular risk for dementia different than the dementia associated with multiple small strokes. However to date, there is no clear evidence that the use of antihypertensive medications reduce the occurrence of Alzheimer's disease.

Heart Disease

High blood pressure is a major risk factor for heart disease.

Heart Attack. About half of people who suffer their first heart attack have moderate hypertension (160/95 mm Hg) or greater. High blood pressure increases the risk for a heart attack by up to five times, depending on the severity of the hypertension.

Heart Failure. Uncontrolled high blood pressure (hypertension) is a major cause of heart failure even in the absence of a heart attack. In fact, about 75% of cases of heart failure start with hypertension. It generally develops as follows:

• The heart muscles thicken to make up for increased blood pressure.
• The force of heart muscle contractions weaken over time, and the muscles have difficulty relaxing. This prevents the normal filling of the heart with blood.

Click the icon to see an image of a hypertensive heart.

Diabetes and Kidney Disease

Diabetes. High blood pressure, and some of the medications used to treat it, can increase the risk for developing diabetes.

End-Stage Kidney Disease. High blood pressure causes 30% of all cases of end-stage kidney disease (medically referred to as end-stage renal disease, or ESRD). Only diabetes leads to more cases of kidney failure. Patients with diabetes and hypertension need to be monitored very closely for the development of kidney disease.

Effect on the Eyes

High blood pressure can injure the blood vessels in the eyes, causing a condition called retinopathy.

Click the icon to see an image of hypertensive retinopathy.

Sexual Dysfunction

Sexual dysfunction is more common and more severe in men with hypertension and in smokers than it is in the general population. Many of the drugs that treat hypertension are thought to cause impotence as a side effect. In these cases, it is reversible when the drugs are stopped. More recent evidence suggests, however, that the disease process that causes hypertension is itself the major cause of erectile dysfunction in these men.

Newer anti-hypertensive drugs, including angiotensin-converting enzyme (ACE) inhibitors and angiotensin-receptor blockers (ARBs), are much less likely to cause erectile dysfunction. Oral phosphodiesterase type 5 (PDE5) inhibitors, such as sildenafil (Viagra), do not appear to pose a risk for men who have both high blood pressure and erectile dysfunction.

Pregnancy, Hypertension, and Preeclampsia

Many women likely to develop hypertension when they are older have their first elevated blood pressure readings during pregnancy. Elevated blood pressure readings generally show up early in pregnancy, before 16 - 20 weeks. (This condition is different than preeclampsia, described just below.) These women often require antihypertensive medications during pregnancy and closer monitoring of themselves and the fetus. Continued hypertension after the pregnancy is also not uncommon.

Severe, sudden high blood pressure in pregnant women is one component of a condition called preeclampsia (commonly called toxemia) that can be very serious for both mother and child. Preeclampsia occurs in up to 10% of all pregnancies, usually in the third trimester of a first pregnancy, and resolves immediately after delivery. Other symptoms and signs of preeclampsia include protein in the urine, severe headaches, and swollen ankles.

The risk for preeclampsia is higher for first births, multiple births, and for very young women (teenagers) and those over age 35. Pre-existing high blood pressure, diabetes, and kidney disease also increase the risk for preeclampsia. There appears to be a genetic component for this condition, so women whose mothers experienced preeclampsia are also at higher risk.

The reduced supply of blood to the placenta can cause low birth weight and eye or brain damage in the fetus. Severe cases of preeclampsia can cause kidney damage, convulsion, and coma in the mother and can be lethal to both mother and child. Evidence also suggests that preeclampsia can lead to increased risks later in life for coronary heart disease and other heart problems.

Women at risk for preeclampsia (particularly those with existing hypertension) are monitored carefully for its presence. Both mother and fetus are monitored closely after a diagnosis. Blood pressure medications may be required. Delivery is the main cure for preeclampsia. In severe cases, the obstetrician will need to induce pre-term birth.

Outlook for Children with Hypertension

Children with high blood pressure should first be treated with lifestyle changes, including weight reduction, increased physical activity, and diet modification. If blood pressure is not controlled with lifestyle changes, drug treatment may be required. Although there are few clinical trials conducted in children, a 2005 study found that the angiotensin receptor blocker losartan was safe and effective in children. Results of studies evaluating outcomes of children with hypertension suggest that early abnormalities, including enlarged heart and abnormalities in the kidney and eyes, may occur even in children with mild hypertension. Children and adolescents with hypertension should be monitored and evaluated for any early organ damage. Secondary hypertension (high blood pressure due to another disease or drug) is more common in children than adults.

Symptoms

Hypertension has aptly been called the "silent killer" because it usually produces no symptoms. Untreated hypertension increases slowly over the years. Everyone 18 years and older should have their blood pressure measured on a regular basis. It is particularly important for anyone with risk factors to have their blood pressure checked regularly and to make appropriate lifestyle changes. Such recommendations are especially important for individuals who have prehypertension or hypertension, a family history of hypertension, are overweight, or are over age 40.

Symptoms of Malignant Hypertension

In rare cases (fewer than 1% of all patients with hypertension), the blood pressure rises quickly (with diastolic pressure usually rising to 130 mm Hg or higher), resulting in malignant or accelerated hypertension. This is a life-threatening condition and must be treated immediately. People with uncontrolled hypertension or a history of heart failure are at increased risk for this crisis.

People should call a doctor immediately if these symptoms occur:

• Drowsiness
• Confusion
• Headache
• Nausea
• Loss of vision
• Respiratory distress (difficulty breathing)

Treatment

Patients with hypertension should work with their doctors to set blood pressure goals based on individual risk factors. Lifestyle and medication programs need to be planned on an individual basis.

Healthy lifestyle changes are imperative for anyone, and are critical for people with even normal blood pressure (120/80 mm Hg) and above. In appropriate patients, aggressive drug treatment of long-term high blood pressure can significantly reduce the incidence of mental decline and death from stroke, heart disease, and other serious physical effects of hypertension. In people with diabetes, controlling both blood pressure and blood glucose levels prevents serious complications of that disease. Anti-hypertensive drugs may even prevent mental decline, including in people genetically susceptible to Alzheimer's disease. Nevertheless, only slightly over half of patients with hypertension are treated at all, and only a quarter have adequately controlled pressure.

It is not clear when drugs should be started, particularly for people with prehypertension or mild high blood pressure. To help make treatment choices, the U.S. National Heart, Lung, and Blood Institute has created categories (denoted as groups A, B, and C) according to a patient's risk factors for heart disease. Applying these categories to the severity of hypertension helps determine whether lifestyle changes alone or medications are needed.

Dozens of anti-hypertensive drugs are available. Most fall into the following categories:

• Diuretics rid the body of extra water and salt. Diuretics are usually the first-line treatment for high blood pressure.
• Beta-blockers block the effects of adrenaline and ease the heart's pumping action.
• Angiotensin converting enzyme (ACE) inhibitorsreduce the production of angiotensin, a chemical that causes arteries to narrow.
• Calcium-channel blockers (CCBs) decrease the contractions of the heart and widen blood vessels.
• Angiotensin-receptor blockers (ARBs) block angiotensin, another chemical that constricts the arteries.
• Vasodilators expand blood vessels.

In about half of patients a single-drug regimen can control mild-to-moderate hypertension. More severe hypertension often requires a combination of two or more drugs. Each drug has specific benefits, but their effects may vary depending on the individual patient.

Side Effects and Problems in Compliance. One of the most difficult issues that patients face, particularly those with primary hypertension, is that the treatment may make them feel worse than the disease, which usually has no symptoms. Whatever the difficulties, compliance with a drug and lifestyle program is worth the effort. It is very important that patients discuss medication concerns with their doctors. If current blood pressure drugs are causing uncomfortable side effects, the doctor may adjust dosages or combinations.

Withdrawal from Anti-Hypertensive Medications. Patients whose blood pressure has been well-controlled and who are able to maintain a healthy life style may choose to withdraw from medications. They should do so in a step-down manner (gradual reduction) and be monitored regularly. Stopping too quickly can have adverse effects, including serious effects on the heart. The highest success rates are more likely in those who lose weight and reduce sodium intake, in patients who have been treated with a single drug, and in those who have maintained lower systolic blood pressure during treatment. People over 75 years old may have more trouble than younger adults in maintaining normal blood pressure after withdrawal.

Lifestyle Changes

Healthy lifestyle changes are an important first step for lowering blood pressure. Current guidelines recommend that people should:

• Exercise at least 30 minutes a day
• Maintain normal weight
• Reduce salt intake
• Increase potassium intake
• Limit alcohol consumption; however, moderate alcohol consumption (1 - 2 glasses a day) may actually lower the risk for heart attack among men with high blood pressure
• Consume a diet rich in fruits, vegetables, and low-fat dairy products while reducing total and saturated fat intake. (The DASH diet is one way of achieving such a dietary plan.)

DASH Diet

The DASH diet (Dietary Approaches to Stop Hypertension) is proven to help lower blood pressure. Results are sometimes seen within a few weeks. Restricting sodium improves results. The diet appears to have antioxidant effects and may help lower LDL cholesterol levels, although beneficial HDL levels also decline. This diet is not only rich in important nutrients and fiber but also includes foods that contain far more electrolytes, potassium (4,700 mg/day), calcium (1,250 mg/day), and magnesium (500 mg/day) than are found in the average American diet.

A diet that is effective in lowering blood pressure is called Dietary Approaches to Stop Hypertension (DASH).

DASH diet recommendations:

• Limit salt intake to no more than 2,300 mg a day (a maximum intake of 1,500 mg a day is an even better goal).
• Reduce saturated fat to no more than 6% of daily calories and total fat to 27% of daily calories. (But, include dairy products that are non- or low-fat. Low-fat dairy products appear to be especially beneficial for lowering systolic blood pressure).
• When choosing fats, select monounsaturated oils, such as olive or canola oils.
• Choose whole grains over white flour or pasta products.
• Choose fresh fruits and vegetables every day. In one study, people who increased their intake of fruits and vegetables experienced a drop in blood pressure after 6 months. Many of these foods are rich in potassium, fiber, or both, possibly helping lower blood pressure.
• Include nuts, seeds, or legumes (dried beans or peas) daily.
• Choose modest amounts of protein (no more than 18% of total daily calories). Fish, skinless poultry, and soy products are the best protein sources.
• Other daily nutrient goals in the DASH diet include limiting carbohydrates to 55% of daily calories and dietary cholesterol to 150 mg. Patients should try to get at least 30 g of daily fiber.

Slight changes to the DASH diet might help further lower blood pressure, as well as improve cholesterol and lipid levels. Researchers reporting in the Journal of the American Medical Association and at the 2005 American Heart Association meeting said that replacing some carbohydrates in the DASH diet with more protein (from plant sources) or monounsaturated fats may help further reduce heart disease risk factors.

Salt Restriction

A combination of the DASH diet and salt restriction is extremely effective in reducing blood pressure. Consuming less than 2,400 mg (about one teaspoon) of sodium (salt) each day is considered helpful for lowering blood pressure. For people over age 50, reducing sodium intake to less than 1,500 mg daily is recommended by some doctors, but many people find it very difficult to achieve this goal. Lowering blood pressure may also help protect against heart failure. Experts disagree on the overall benefits of salt restriction for everyone. Still, the following people should take particular measures to restrict salt:

• People at Risk for Salt-Sensitivity. About half of people with hypertension have blood pressure that reacts significantly to salt. Such people are known as salt-sensitive. Among those at highest risk for salt sensitivity are African-Americans, people with diabetes, and elderly people.
• Overweight People. Overweight individuals may absorb and retain sodium differently from people with normal weights. High sodium intake may be associated with an increased risk of heart disease and all-cause mortality in overweight, but not in normal weight, people. Reducing sodium can also help reduce the risk of stroke in people who are overweight.
• People on Anti-Hypertensive Drugs. Restricting salt also enhances the benefits of many standard anti-hypertensive drugs by reducing potassium loss, and may help protect against kidney disease in patients who are also taking calcium-blocker drugs. A low-salt diet can also increase the chances for being able to stop such medications.

Simply eliminating table and cooking salt can be beneficial. Salt substitutes, such as Cardia (containing mixtures of potassium, sodium, and magnesium), are available, but they are expensive. Talk with your doctor before using a salt substitute product. About 75% of the salt in the typical American diet comes from processed or commercial foods, not from food cooked at home, so the benefits of table-salt substitutes are likely to be very modest. Some sodium is essential to protect the heart, but most experts agree that the amount is significantly less than that found in the average American diet. If people cannot significantly reduce the amount of salt in their diets, adding potassium-rich foods may help to restore a healthy balance.

Potassium

Evidence strongly indicates that a potassium-rich diet can help achieve healthy blood pressure levels, and that potassium supplements can lower systolic blood pressure by 1.8 m Hg and diastolic blood pressure by 1 mm Hg. Some evidence suggests that a potassium-rich diet can reduce the risk of stroke by 22 - 40%. Current expert guidelines support the use of potassium supplements or enough dietary potassium to achieve 3,500 mg per day for people with normal or high blood pressure (who have no risk factors for excess potassium levels). This goal is particularly important in people who have high sodium intake.

The best source of potassium is the fruits and vegetables that contain them. Some potassium-rich foods include bananas, oranges, pears, prunes, cantaloupes, tomatoes, dried peas and beans, nuts, potatoes, and avocados.

Excess potassium can cause abdominal distress, muscle weakness, and, in rare cases, dangerous heart problems. Some people should be particularly cautious about excess potassium, including those with conditions that increase potassium levels, such as diabetes or kidney disease. People who take medications that limit the kidney's ability to excrete potassium, such as ACE inhibitors or potassium-sparing diuretics, should not take potassium supplements.

Caffeine, Alcohol, and Smoking

Smoking. Everyone should quit smoking.

Alcohol. People who drink alcohol should do so in moderation. Men with hypertension should limit their intake to no more than one or two drinks a day, and women and lighter people should drink less.

Caffeine Drinks. Coffee drinking is associated with small increases in blood pressure, but the risk is very small in people with normal blood pressure. People with existing hypertension should avoid caffeine altogether.

Other Dietary Considerations

Fiber. Fiber supplementation can help reduce blood pressure levels. It may take up to 8 weeks to achieve the maximum benefit.

Folate. Increasing folate (a B vitamin) intake to more than 800 mcg/day may help reduce blood pressure, particularly for younger women (under age 46). Dietary sources of folate include citrus fruits, leafy green vegetables, beans, and grain products. Folate helps reduce homocysteine levels.

Fish Oil and Omega 3 Fatty Acids. Omega 3 fatty acids (docosahexaenoic and eicosapentaneoic acids) are found in oily fish. Studies indicate that they may have specific benefits for many medical conditions, including hypertension. They appear to help keep blood vessels flexible and may help protect the nervous system. Fatty acids are also available in supplements, but their long-term effects on blood pressure are unknown.

Click the icon to see an image of omega-3 fatty acids

Calcium. Calcium regulates the tone of the smooth muscles lining blood vessels. Studies have found that people who have sufficient dietary calcium have lower blood pressure than those who do not. Hypertension itself increases calcium loss from the body. The effects of extra calcium on blood pressure, however, are mixed, with some even showing higher pressure.

Click the icon to see an image of the sources of calcium.

Magnesium. Some studies reported that magnesium supplements may induce small but significant reductions in blood pressure. No major studies, however, have been done on long-term benefits or risks of magnesium supplements. One major study on diet found no effect on blood pressure from magnesium intake from foods.

Antioxidant Supplements. Antioxidants are substances that help the body eliminate oxidants (also called oxygen-free radicals), which are damaging particles produced as part of the body's chemical processes. Some antioxidant supplements, including vitamins C and E and alpha-lipoic acid, are being studied for possible benefits in protecting against hypertension by preventing injury in the blood vessels. Vitamin C may have specific benefits for hypertension by preventing dangerous effects on nitric acid, the substance that keeps arteries flexible.

Click the icon to see an image of vitamin C sources.

Click the icon to see an image of vitamin E sources.

Weight Loss

Even modest weight loss in overweight people, particularly in the abdominal area, can immediately lower blood pressure. Weight loss, especially when accompanied by salt restriction, may allow patients with mild hypertension, even older people, to safely reduce or go off medications. The benefits of weight loss on blood pressure are long-lasting.

Exercise

Positive Effects on Blood Pressure. Regular exercise helps keep arteries elastic, even in older people, which in turn ensures blood flow and normal blood pressure. Sedentary people have a 35% greater risk of developing hypertension than athletes.

Experts recommend at least 30 minutes of exercise on most days. In one study, moderate exercise (jogging 2 miles per day) controlled hypertension so well that more than half the patients who had been taking drugs for high blood pressure were able to discontinue their medication.

Studies have also indicated that yoga and Tai Chi, an ancient Chinese exercise involving slow, relaxing movements, may lower blood pressure almost as well as moderate-intensity aerobic exercises.

High-intensity exercise may not lower blood pressure as effectively as moderate intensity exercise and may be dangerous in people with hypertension.

Negative Effects. Each year an estimated 75,000 heart attacks (5% of all heart attacks) occur after heavy exertion, leading to 25,000 deaths. Older people and those with uncontrolled hypertension or other serious medical conditions should be cautious when exercising. Studies report that older people who begin vigorous exercise are at a slightly higher than average risk for a heart attack during the first year, but over time, regular exercise is likely to be protective.

The following activities may pose particular dangers for high-risk individuals:

• Intense workouts (snow shoveling, slow jogging, speed walking, tennis, heavy lifting, heavy gardening). They tend to stress the heart, raise blood pressure for a brief period, and may cause spasms in the arteries leading to the heart.
• Competitive sports, which couple intense activity with aggressive emotions.

Effects of Anti-Hypertensive Drugs on Exercise. Certain anti-hypertensive medications, including diuretics and beta-blockers, can interfere with exercise capacity. ACE inhibitors or calcium-channel blockers are the best drugs for active individuals. However, patients who take drugs that interfere somewhat with exercise capability should still adhere to an exercise program and consult a doctor on how best to balance medications with exercise.

Click the icon to see an image about lifestyle changes for hypertension.

Good Sleep Habits

Certain sleep disorders, especially sleep apnea, are associated with hypertension. Even chronic, insufficient sleep may raise blood pressure in patients with hypertension, placing them at increased risk of heart disease and death. Stress hormone levels increase with sleeplessness, which can activate the sympathetic nervous system, a strong player in hypertension. Patients who have chronic insomnia or other severe sleep disturbances (particularly sleep apnea) may want to consult a sleep expert. Patients with hypertension who are habitually poor sleepers should consider long-acting blood pressure medications to help counteract the increase in blood pressure that occurs in the early morning hours.

Stress Reduction and Psychological Considerations

Improving mood or relieving stress may be helpful. The following studies suggested possible benefits:

• Stress reduction programs that use cognitive-behavioral therapy may reduce blood pressure.
• Active religious faith was associated with healthy blood pressure levels, possibly indicating the combined benefits of a strong social network and reduced stress from spiritual activities.
• A simple relaxation technique called transcendental meditation (TM), which involves silent repetition of a single sound, was associated with lower blood pressure.

Treating stress cannot cure medical problems. Stress management programs are not a substitute for standard medical treatments, but they can be a very important component of a lifestyle plan.

Classes of Medications

Several classes of drugs can treat hypertension.

Diuretics

Diuretics help the kidneys get rid of excess salt and water. They are the mainstays of anti-hypertensive therapy and are often the first drug selected for most people with hypertension. They are also especially helpful for treating patients with heart failure, patients with isolated systolic hypertension, the elderly, and African-Americans. (African-Americans are more likely to be salt-sensitive, so they respond well to these drugs.) They also work well for patients with diabetes.

Results of a major long-term study have suggested that diuretics work just as well as newer drugs in lowering blood pressure and are more effective in preventing heart failure, heart attack, and stroke. In the study, the benefits of the diuretic were even more significant for African-American patients. Other trial results indicated that patients taking a calcium channel blocker had the greatest risk for heart failure, and that an ACE inhibitor was much less effective than the diuretic in lowering blood pressure and preventing stroke in African-American patients.

Diuretic Types and Brands. The many brands of diuretics are generally inexpensive. Some need to be taken once a day, some twice a day. Low doses are usually as effective for lowering blood pressure as higher doses. Diuretics are usually used in combination with other drugs, especially ACE inhibitors and beta blockers.

The three main types of diuretics include:

• Thiazide diuretics. These include chlorothiazide (Diuril), chlorthalidone (Hygroton), indapamide (Lozol), hydrochlorothiazide (Esidrix, HydroDiuril), bendroflumethiazide (Naturen), methylclothiazide, (Edduran), and metolazone (Mykrox, Zaroxolyn). In most cases, thiazides are preferred to other diruetics for treatment of high blood pressure.
• Potassium-sparing diuretics. These include amiloride (Midamor), spironolactone (Aldactone), and triamterene (Dyrenium).
• Loop diuretics. Because loop diuretics act faster than other diuretics it is important to avoid dehydration and potassium loss. Loop diuretics include bumetanide (Bumex), furosemide (Lasix), ethacrynic acid (Edecrin), and torsemide (Demadex).

Problems with Diuretics.

• Loop and thiazide diuretics reduce the body's supply of potassium, which, if left untreated, increases the risk for arrhythmias. Arrhythmias are heart rhythm disturbances that can, rarely, lead to cardiac arrest. In these cases, doctors will prescribe lower doses of the current diuretic, recommend potassium supplements, or use potassium-sparing diuretics either alone or in combination with a thiazide.
• Potassium-sparing drugs have their own risks, which include dangerously high levels of potassium in people with existing elevated levels of potassium or in those with damaged kidneys. However, all diuretics are generally more beneficial than harmful.
• Thiazide diuretics may increase blood sugar levels.
• Erectile dysfunction (impotence) may be a side effect of thiazides.
• Elevated uric acid levels, and possibly gout, may be caused by thiazide diuretics.

Common Diuretic Side Effect Symptoms.

• Fatigue
• Depression and irritability
• Urinary incontinence
• Reduced sexual drive and problems with obtaining and maintaining an erection

Beta-Blockers

Beta-blockers help slow heart rate and lower blood pressure. They are usually used in combination with other drugs such as ACE inhibitors and diuretics. Beta-blockers are more likely to be used to treat hypertension in patients with angina, previous heart attack, heart failure, arrhythmias with fast heart rates, or migraine headaches.

Brands. Propranolol Propranolol (Inderal), acebutolol (Sectral), atenolol (Tenormin), betaxolol (Kerlone), carteolol (Cartrol), metoprolol (Lopressor), nadolol (Corgard), penbutolol (Levatol), pindolol (Visken), carvedilol (Coreg), timolol (Blocadren), and nebivolol (Bystolic). The drugs may differ in their effects and benefits.

Problems with Beta-Blockers.

• Do not abruptly stop taking these drugs. The sudden withdrawal of beta-blockers can rapidly increase heart rate and blood pressure and potentially cause angina or heart attack. If you need to stop your beta-blocker, the doctor may want you to slowly decrease the dose before stopping completely.
• Beta-blockers are categorized as non-selective or selective. Non-selective beta blockers, such as carvedilol and propranolol, may sometimes narrow bronchial airways. Patients with asthma, emphysema, or chronic bronchitis should not use these medicines.
• Beta-blockers may lower HDL (good) cholesterol.
• These drugs can hide warning signs of low blood sugar (hypoglycemia) in patients with diabetes. When combined with a diuretic, the risk of diabetes may increase.

Common Side Effects.

• Fatigue and lethargy
• Vivid dreams and nightmares
• Depression
• Memory loss
• Dizziness and lightheadedness
• Reduced ability to exercise
• Coldness in extremities (legs, toes, arms, hands)
• Reduced sexual drive and problems with obtaining and maintaining an erection

Check with your doctor about any side effects. Do not stop taking these drugs on your own.

ACE Inhibitors

Angiotensin-converting enzyme (ACE) inhibitors open blood vessels and decrease the workload of the heart. They treat high blood pressure but can also help protect the heart and kidneys.

Patients with heart failure or an enlarged left ventricle, previous heart attack, diabetes, or kidney disease are considered particularly good candidates for ACE inhibitors as part of treatment for high blood pressure.

ACE inhibitors are particularly important for patients with diabetes and heart failure. A large study reported that patients with diabetes who took these drugs had fewer heart attacks and lower overall mortality rates than patients who took other types of high blood pressure medications. ACE inhibitors may also help slow progression of kidney disease, in addition to controlling blood pressure.

Aspirin is recommended for preventing death in patients with heart disease, and can safely be used in combinatin with ACE inhibitors, particularly at lower dosages of aspirin (75 - 81 mg).

Brands. ACE inhibitors include captopril (Capoten), enalapril (Vasotec), quinapril (Accupril), benazepril (Lotensin), ramipril (Altace), perindopril (Aceon), and lisinopril (Prinivil, Zestril).

Common Side Effects of ACE Inhibitors.

• Low blood pressure is the main side effect of ACE inhibitors. This can be severe in some patients, especially at the start of therapy.
• Irritating cough is a common side effect, which some people find intolerable. ACE inhibitors can have this side effect, but angiotensin-receptor blockers do not.
• ACE inhibitors can harm a developing fetus and should not be used during pregnancy. While it has long been known that these drugs can cause problems in the second and third trimester, an important 2006 study indicated that ACE inhibitors can also cause major heart birth defects when taken during the first trimester. The Food and Drug Administration (FDA) and the American Heart Association recommend that women who become pregnant should change from ACE inhibitors to another type of blood pressure drug as soon as possible. Women of child-bearing age who are considering becoming pregnant should also discuss other medicines with their doctors.

Uncommon Side Effects of ACE Inhibitors.

• ACE inhibitors protect against kidney disease, but they may also increase potassium retention by the kidneys. If potassium levels become extremely high, they can cause the heart to stop beating (cardiac arrest). This side effect is rare, except in patients with significant kidney disease. Because of this risk, ACE inhibitors are not usually used in combination with potassium-sparing diuretics or potassium supplements.
• A rare but severe side effect is granulocytopenia, an extreme reduction in infection-fighting white blood cells.
• In very rare cases, patients suffer a sudden and severe allergic reaction, called angioedema that causes swelling in the eyes and mouth and may close off the throat.

Patients who have difficulty tolerating ACE inhibitor side effects are usually switched to an angiotensin-receptor blocker (ARB).

Angiotensin-Receptor Blockers (ARBs)

ARBs, also known as angiotensin II receptor antagonists, are similar to ACE inhibitors in their ability to open blood vessels and lower blood pressure. They may have fewer or less-severe side effects than ACE inhibitors, especially coughing, and are sometimes prescribed as an alternative to ACE inhibitors. In general they are prescribed to patients who cannot tolerate or did not respond to ACE inhibitors.

Brands. Losartan (Cozaar, Hyzaar), olmesartan (Benicar) candesartan (Atacand), telmisartan (Micardis), eprosartan (Teveten), irbesartan (Avapro), and valsartan (Diovan). A combination medication containing candesartan and the diuretic hydrochlorothiazide (Diovan HCT, Atacand HCT) is also available.

Side Effects.

• Low blood pressure
• Dizziness and lightheadedness
• Raised potassium levels
• Drowsiness
• Nasal congestion
• Should not be used during pregnancy

Calcium-Channel Blockers (CCBs)

Calcium-channel blockers (CCBs), or calcium antagonists, help relax blood vessels. Along with diuretics, CCBs may work better than other drug classes for lowering blood pressure in African-Americans. Recent research indicates that newer types of drugs (CCBs, ACE inhibitors) may be a better treatment option for some patients than older drugs (especially beta-blockers).

Brands. Diltiazem (Cardizem, Dilacor), amlodipine (Norvasc), felodipine (Plendil), isradipine (DynaCirc), verapamil (Calan, Isoptin, Verelan), nisoldipine (Sular), nicardipine (Cardene), nifedipine (Adalat, Procardia), lercanidipine (Zanidip), lacidipine (Motens), and nitrendipine (Nitrepin). In 2004, a dual-therapy calcium channel blocker-statin combination drug (Caduet) was approved to treat high blood pressure and high cholesterol. Caduet is a fixed-dose combination of amlodipine and atorvastatin.

Side Effects.

• Swelling in the feet
• Constipation
• Fatigue
• Erectile dysfunction
• Gingivitis
• Rash
• Food interactions (do not take CCBs with grapefruit or Seville orange products)

Alpha Blockers

Alpha blockers such as doxazosin (Cardura), prazosin (Minipress), and terazosin (Hytrin) help widen small blood vessels. They are generally not used as first-line drugs for high blood pressure, but are prescribed if other drugs do not work or as add-on medication.

Vasodilators

Vasodilators help open blood vessels by relaxing muscles in the blood vessel walls. These drugs are usually used in combination with a diuretic or a beta-blocker. They are rarely used by themselves. Vasodilators include hydralazine (Apresoline), clonidine (Catapres), and Minoxidil (Loniten). Some of these drugs should be used with caution or not at all in people who have angina or who have had a heart attack.

Other Drugs

Aliskiren (Tekturna). In 2007, the FDA approved aliskiren for treatment of high blood pressure. Aliskiren can be taken either alone or in combination with other blood pressure medication. It should not be used during pregnancy as it can cause injury or death to the fetus. Aliskiren is the first hypertension drug that inhibits renin, a kidney enzyme associated with the regulation of blood pressure.

Statins. Statins, common drugs used to lower cholesterol, are proving to have many other health benefits. They include lovastatin (Mevacor), pravastatin (Pravachol), simvastatin (Zocor), fluvastatin (Lescol), atorvastatin (Lipitor), and rosuvastatin (Crestor). In an important 2002 study, patients with high blood pressure but normal or slightly high cholesterol levels had fewer heart attacks and strokes when they took a statin. In 2004, a calcium channel blocker-statin combination drug (Caduet) was approved to treat simultaneously high blood pressure and high cholesterol. Caduet is a fixed-dose combination of amlodipine and atorvastatin.

Resources

• www.acc.org -- American College of Cardiology
• www.americanheart.org -- American Heart Association
• www.ash-us.org -- American Society of Hypertension
• www.nhlbi.nih.gov/hbp -- National Heart, Lung, and Blood Institute
• www.nhlbi.nih.gov/health/public/heart/hbp/dash -- DASH diet
• www.ishib.org -- International Society on Hypertension in Blacks
• www.eatright.org -- American Dietetic Association

References

AHA; ACC; National Heart, Lung, and Blood Institute, Smith SC Jr, Allen J, Blair SN, Bonow RO, Brass LM, Fonarow GC, et al. AHA/ACC guidelines for secondary prevention for patients with coronary and other atherosclerotic vascular disease: 2006 update endorsed by the National Heart, Lung, and Blood Institute. J Am Coll Cardiol. 2006 May 16;47(10):2130-9.

Alajmi M, Mulgrew AT, Fox J, Davidson W, Schulzer M, Mak E, et al. Impact of continuous positive airway pressure therapy on blood pressure in patients with obstructive sleep apnea hypopnea: a meta-analysis of randomized controlled trials. Lung. 2007 Mar-Apr;185(2):67-72. Epub 2007 Mar 28.

Barzilay JI, Davis BR, Cutler JA, Pressel SL, Whelton PK, Basile J, et al. Fasting glucose levels and incident diabetes mellitus in older nondiabetic adults randomized to receive 3 different classes of antihypertensive treatment: a report from the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT). Arch Intern Med. 2006 Nov 13;166(20):2191-201.

Bellamy L, Casas JP, Hingorani AD, Williams DJ. Pre-eclampsia and risk of cardiovascular disease and cancer in later life: systematic review and meta-analysis. BMJ. 2007 Nov 10;335(7627):974. Epub 2007 Nov 1.

Beulens JW, Rimm EB, Ascherio A, Spiegelman D, Hendriks HF, Mukamal KJ. Alcohol consumption and risk for coronary heart disease among men with hypertension. Ann Intern Med. 2007 Jan 2;146(1):10-9.

Connolly HM, Oh JK. Echocardiography. In: Libby P, Bonow RO, Mann DL, Zipes DP, eds. Libby: Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 8th ed. Saunders; 2007:chap 14.

Din-Dzietham R, Liu Y, Bielo MV, Shamsa F. High blood pressure trends in children and adolescents in national surveys, 1963 to 2002. Circulation. 2007 Sep 25;116(13):1488-96. Epub 2007 Sep 10.

Djousse L, Pankow JS, Hunt SC, Heiss G, Province MA, Kabagambe EK, et al. Influence of saturated fat and linolenic acid on the association between intake of dairy products and blood pressure. Hypertension. 2006 Aug;48(2):335-41.

Fagard RH, Cornelissen VA. Incidence of cardiovascular events in white-coat, masked and sustained hypertension versus true normotension: a meta-analysis. J Hypertens. 2007 Nov;25(11):2193-8.

Forman JP, Rimm EB, Curhan GC. Frequency of analgesic use and risk of hypertension among men. Arch Intern Med. 2007 Feb 26;167(4):394-9.

Gami AS and Somers VK. Sleep apnea and cardiovascular disease. In: Libby P, Bonow RO, Mann DL, Zipes DP, eds. Libby: Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 8th ed. Saunders; 2007:chap 74.

Hansen ML, Gunn PW, Kaelber DC. Underdiagnosis of hypertension in children and adolescents. JAMA. 2007 Aug 22;298(8):874-9.

Kaplan NM. Systemic hypertension: therapy. In: Libby P, Bonow RO, Mann DL, Zipes DP, eds. Libby: Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 8th ed. Saunders; 2007:chap 41.

Kehoe PG, Wilcock GK. Is inhibition of the renin-angiotensin system a new treatment option for Alzheimer's disease? Lancet Neurol. 2007 Apr;6(4):373-8.

Magnussen EB, Vatten LJ, Lund-Nilsen TI, Salvesen KA, Davey Smith G, Romundstad PR. Prepregnancy cardiovascular risk factors as predictors of pre-eclampsia: population based cohort study. BMJ. 2007 Nov 10;335(7627):978. Epub 2007 Nov 1.

Matchar DB, McCrory DC, Orlando LA, Patel MR, Patel UD, Patwardhan MB, et al. Systematic review: comparative effectiveness of angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers for treating essential hypertension. Ann Intern Med. 2008 Jan 1;148(1):16-29. Epub 2007 Nov 5.

Peila R, White LR, Masaki K, Petrovitch H, Launer LJ. Reducing the risk of dementia: efficacy of long-term treatment of hypertension. Stroke. 2006 May;37(5):1165-70.

Thornley-Brown D, Wang X, Wright JT Jr, Randall OS, Miller ER, Lash JP, et al. Differing effects of antihypertensive drugs on the incidence of diabetes mellitus among patients with hypertensive kidney disease. Arch Intern Med. 2006 Apr 10;166(7):797-805.

Victor RG and Kaplan NM. Systemic hypertension: mechanisms and diagnosis. In: Libby P, Bonow RO, Mann DL, Zipes DP, eds. Libby: Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 8th ed. Saunders; 2007:chap 40.

Wolff T, Miller T. Evidence for the reaffirmation of the U.S. Preventive Services Task Force recommendation on screening for high blood pressure. Ann Intern Med. 2007 Dec 4;147(11):787-91.

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. 1997- A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.