GLOSSARY

Hypothyroidism is a condition in which thyroid hormone production or action is inadequate, slowing the body’s metabolism; about 2–5 percent of the population (more often women and older adults) have overt disease and up to 10 percent subclinical disease.

Causes

• Hashimoto’s thyroiditis (autoimmune): the most common cause in iodine-sufficient areas; anti-TPO antibodies positive.
• Iodine deficiency: the most common cause worldwide.
• Treatments: radioactive iodine, thyroid surgery, and drugs (lithium and amiodarone).
• Secondary: pituitary disease (rare).
• Congenital: detected by newborn screening (about 1 in 2,000–4,000).

Symptoms

Fatigue, weight gain (usually modest, mainly fluid retention), cold intolerance, constipation, dry skin, hair loss, mental slowing, depression, heavy periods, slow heart rate, and raised cholesterol.

Diagnosis and Treatment