Early symptoms:

• weakness
• fatigue
• cold intolerance
• constipation
• weight gain (unintentional)
• depression
• joint or muscle pain
• thin, brittle fingernails
• thin and brittle hair
• paleness

Late symptoms:

• slow speech
• dry flaky skin
• thickening of the skin
• puffy face, hands and feet
• decreased taste and smell
• thinning of eyebrows
• hoarseness
• abnormal menstrual periods

Additional symptoms that may be associated with this disease:

• overall swelling
• muscle spasms (cramps)
• muscle pain
• muscle atrophy
• uncoordinated movement
• absent menstruation
• joint stiffness
• dry hair
• hair loss
• facial swelling
• drowsiness
• appetite loss
• ankle, feet, and leg swelling
• short stature
• separated sutures
• delayed formation or absence of teeth

A physical examination reveals delayed relaxation of muscles during tests of reflexes. Pale, yellow skin; loss of the outer edge of the eyebrows; thin and brittle hair; coarse facial features; brittle nails; firm swelling of the arms and legs; and mental slowing may be noted. Vital signs may reveal slow heart rate, low blood pressure, and low temperature.

A chest X-ray may reveal an enlarged heart.

Laboratory tests to determine thyroid function include:

• T4 test (low)
• serum TSH (high in primary hypothyroidism, low or low-normal in secondary hypothyroidism)

Additional laboratory abnormalities may include:

• increased cholesterol levels
• increased liver enzymes
• increased serum prolactin
• low serum sodium
• a complete blood count (CBC) that shows anemia