Hypothyroidism

The thyroid produces hormones that influence the body’s metabolism. Hypothyroidism occurs when the thyroid gland is underactive and does not make enough thyroid hormone.

Symptoms of hypothyroidism may include constipation, cold intolerance, fatigue or weakness, paleness or dry skin, depression, weight gain, and thin, brittle hair or fingernails, among others.

The most common cause of hypothyroidism is thyroiditis, which is swelling and inflammation of the thyroid gland. Thyroiditis may be caused by the immune system attacking the thyroid gland, viral infections such as the common cold, or pregnancy which is called postpartum thyroiditis. Other causes of hypothyroidism include certain medicines, such as lithium and amiodarone, congenital hypothyroidism, radiation treatments to the neck or brain, radioactive iodine used to treat an overactive thyroid gland, or surgical removal of part or all of the thyroid gland among others.

The goal for treatment is replacing the thyroid hormone as well as obtaining and keeping TSH in the normal range. Levothyroxine is the most commonly used medicine, a synthetic thyroid hormone. 

The thyroid gland is an important organ of the endocrine system. It is located at the front of the neck, just above where your collarbones meet. The thyroid makes hormones that control the way every cell in the body uses energy. This process is called metabolism.

The most common cause of hypothyroidism is thyroiditis, which is swelling and inflammation of the thyroid gland.

Thyroiditis may be caused by:

• The immune system attacking the thyroid gland
• Viral infections such as the common cold
• Pregnancy which is called postpartum thyroiditis

Hypothyroidism may be caused by:

• Certain medicines, such as lithium and amiodarone
• Congenital hypothyroidism. In this case, babies are born without a thyroid, with a partly formed one, or the thyroid is in the wrong location.
• Radiation treatments to the neck or brain
• Radioactive iodine used to treat an overactive thyroid gland
• Surgical removal of part or all of the thyroid gland
• Sheehan syndrome, which is a condition when a woman bleeds severely during pregnancy or childbirth and causes the destruction of the pituitary gland
• Pituitary tumor or pituitary surgery

Hypothyroidism is more common in women and people over age 50.

See your doctor for ongoing fatigue, weight gain, feeling cold, constipation, or dry skin and hair. A simple blood test can confirm the diagnosis, and treatment is usually very effective.