Symptoms depend on which type of nerve is affected. The three main types of nerves are sensory, motor, and autonomic. Neuropathy can affect any one or a combination of all three types of nerves. Symptoms also depend on whether the condition affects the whole body or just one nerve (as from an injury).

SENSATION CHANGES

Damage to sensory fibers results in changes in sensation, ranging from abnormal sensations (burning, nerve pain, or tingling), numbness , or an inability to determine joint position in the area, which causes incoordination.

For many neuropathies, sensation changes often begin in the feet and progress toward the center of the body with involvement of other areas as the condition worsens.

MOVEMENT DIFFICULTIES

Damage to the motor fibers interferes with muscle control and can cause weakness, loss of muscle bulk, and loss of dexterity. Sometimes, cramps are a sign of motor nerve involvement.

Other muscle-related symptoms include:

• lack of muscle control
• difficulty or inability to move a part of the body (paralysis)
• muscle atrophy
• muscle twitching (fasciculation) or cramping
• difficulty breathing or swallowing
• falling (from legs buckling or tripping over toes)
• lack of dexterity (i.e. unable to button a shirt)

AUTONOMIC SYMPTOMS

The autonomic nerves control involuntary or semi-voluntary functions, such as control of internal organs and blood pressure. Damage to autonomic nerves can cause:

• blurred vision
• decreased ability to sweat (anhidrosis)
• dizziness that occurs when standing up or fainting associated with a fall in blood pressure
• heat intolerance with exertion (decreased ability to regulate body temperature)
• nausea or vomiting after meals
• abdominal bloating (swelling)
• feeling full after eating a small amount (early satiety)
• diarrhea
• constipation
• unintentional weight loss (more than 5% of body weight)
• urinary incontinence
• feeling of incomplete bladder emptying
• difficulty beginning to urinate (urinary hesitancy)
• male impotence

• EMG (a recording of electrical activity in muscles)
• Nerve conduction tests
• Nerve biopsy
• Blood tests to screen for medical conditions, such as diabetes and vitamin deficiency, among others.