Signs and symptoms of hypothyroidism vary significantly from patient to patient and often develop slowly. It can take years before symptoms become obvious. In some cases, symptoms may progress over time.

Initially, many patients report fatigue and sluggishness. Over time, more obvious symptoms may emerge, including puffiness of the face, increased sensitivity to cold and unexplained weight gain.

Other symptoms may include:

• Constipation
• Puffiness around the eyes and ankles (edema)
• Depression or changes in personality
• Forgetfulness, impaired concentration or confusion
• Dry, pale, scaly or thick skin
• Dry hair or loss of hair
• Heavy menstrual periods
• Enlarged thyroid (goiter)
• Hoarseness or slow speech
• Muscle aches, weakness, stiffness and tenderness
• Muscle cramps
• Pain, stiffness or swelling in the joints
• Rise in blood cholesterol levels

  

• Dull facial expression
• Burning mouth syndrome

Hypothyroidism is more likely to affect adults than children. However, babies sometimes are born without a thyroid gland or with a gland that does not function properly. Symptoms of hypothyroidism in young children may include:

• Constipation
• Excessive sleepiness
• Frequent choking
• Large and protruding tongue
• Poor muscle tone
• Muscle swelling (hypertrophy)
• Yellowing of the skin and whites of the eyes (jaundice)
• Growth retardation

Left untreated, hypothyroidism in young children can lead to severe physical disabilities and mental retardation. Children may experience poor growth and delayed development of permanent teeth. Poor mental development and delayed onset of puberty also may occur in these children.

Patients of any age whose hypothyroidism goes untreated are at risk for developing an advanced form of the illness known as myxedema. This rare condition is potentially life-threatening and requires prompt medical attention. Symptoms associated with myxedema include:

• Drowsiness that can progress to profound lethargy and coma
• Decreased body temperature
• Decreased breathing
• Intense intolerance to cold
• Low blood pressure (hypotension), which may cause dizziness or fainting