Symptoms:

Early Symptoms and Complaints. Early symptoms of hypothyroidism are subtle and, in older people, can be easily mistaken for symptoms of stress or aging. They include:

• Chronic fatigue
• Difficulty concentrating
• Sensitivity to cold
• Headache
• Muscle and joint aches
• Weight gain, despite diminished appetite
• Constipation
• Dry skin
• Early puberty
• Menstrual irregularities (either heavier-than-normal or lighter-than-normal bleeding)
• Milky discharge from the breasts (galactorrhea)

In premenopausal women, early symptoms can interfere with fertility. A history of miscarriage may be a sign of impending hypothyroidism. Studies suggest that even if thyroid levels are normal, women who have a history of miscarriages often have antithyroid antibodies during early pregnancy and are at risk for developing autoimmune thyroiditis over time.

Later Symptoms. As free thyroxine levels fall over the following months, other symptoms may develop:

• Impaired mental activity, including concentration and memory, particularly in the elderly.
• Depression. Some experts believe that even mild thyroid failure may increase susceptibility to major depression.
• Muscle weakness, numbness, pain, and cramps. This can cause an unsteady gait. Muscle cramps are common, and carpal tunnel syndrome or symptoms similar to arthritis sometimes develop. In some cases, the arms and legs may feel numb.
• Numbness in the fingers.
• Hearing loss.
• Husky voice.
• Continuing weight gain and possible obesity, in spite of low appetite.
• Some people experience less sweating, and their skin becomes pale.
• Skin and hair changes. Skin becomes pale, rough, and dry. Patients may sweat less. Hair coarsens and even falls out. Nails become brittle.
• Snoring and obstructive sleep apnea (a condition in which in the soft palate in the throat collapses at intervals during sleep, thereby blocking the passage of air).

Symptoms of Secondary (Pituitary-Related) Hypothyroidism

Secondary hypothyroidism, caused by tumors or other growths on the pituitary, produces the usual symptoms of primary hypothyroidism. In addition, other symptoms may be present depending on what part of the pituitary gland may be involved and how large the tumor is. Symptoms of secondary hypothyroidism include:

• Sexual drive and fertility may be impaired in both men and women
• Galactorrhea (milky discharge from the breasts)
• Patients may feel exhausted, crave salt, and have low blood pressure
• Headaches and visual disturbances may develop

Hypothyroidism occurs when the thyroid gland is underactive. The condition may affect all body functions. The rate of metabolism slows, causing mental and physical sluggishness. Myxedema, a medical emergency, is the most severe form of hypothyroidism. A problem with the thyroid itself (primary) or malfunction of the pituitary gland (secondary) or hypothalamus (tertiary) can cause hypothyroidism.

Symptoms in Infants and Children

All babies are now screened for hypothyroidism in order to prevent retardation that can occur if treatment is delayed. Symptoms of hypothyroidism in children vary depending on when the problem first develops.

• Most children who are born with a defect that causes congenital hypothyroidism have no obvious symptoms. Symptoms that do appear in newborns may include jaundice (yellowish skin), noisy breathing, and an enlarged tongue.
• Early symptoms of undetected and untreated hypothyroidism in infants include feeding problems, failure to thrive, constipation, hoarseness, and sleepiness.
• Later on, symptoms in untreated children include protruding abdomens; rough, dry skin; and delayed teething. Rarely, in advanced cases, yellow raised bumps (called xanthomas) may appear under the skin, the result of cholesterol build-up.
• If they do not receive proper treatment in time, children with hypothyroidism may be extremely short for their age, have a puffy, bloated appearance, and have below-normal intelligence. Any child whose growth is abnormally slow should be examined for hypothyroidism.