Feeling tired and worn down? Gaining weight for no reason? Feel cold all the time?

These are some of the symptoms of a glandular disorder called hypothyroidism.

What is hypothyroidism?

Hypothyroidism is a lack of thyroid hormone. It develops when the thyroid gland does not produce enough of the hormone, which controls the way the body uses energy. A lack of thyroid hormone affects all body systems.

The risk of developing hypothyroidism tends to increase with age; older women have the highest risk. In rare cases, hypothyroidism occurs in infants and children. Infants will grow and develop normally if hypothyroidism is treated within the first month of life. Untreated hypothyroidism in infants can cause brain damage, leading to mental retardation and developmental delays. Every state in the United States tests newborns for hypothyroidism.

Teens with hypothyroidism typically look much younger than their age. With proper treatment, a teen will catch up in weight and height to healthy teens of the same age.

In adults, untreated hypothyroidism can cause several complications, including fluid around the heart and an increase in the levels of cholesterol and triglycerides (increasing the risk of coronary artery disease and stroke). Severe hypothyroidism can cause a life-threatening condition called myxedema coma.

Whether untreated hypothyroidism gets better or worse depends on its cause and your age. Hypothyroidism caused by Hashimoto's thyroiditis—a disease in which the body's natural defense (immune) system attacks the thyroid gland—occasionally will disappear on its own. More often, you will have a gradual loss of thyroid function.

Women may develop hypothyroidism during or after pregnancy. Hypothyroidism that developed before pregnancy may become worse during pregnancy.

What causes hypothyroidism?

Hashimoto's thyroiditis is the most common cause of hypothyroidism in the United States. Other common causes include surgical removal of the thyroid gland, radioactive iodine therapy, and thyroiditis after childbirth.

Less common causes include:

Viral and bacterial infections of the thyroid gland.

Problems with the pitutary gland or the hypothalamus (areas of the brain that produce hormones).

Too little or too much iodine in the diet (rarely seen in Western countries).

Some medications, including lithium carbonate and interferon alfa.

Congenital hypothyroidism (present from birth).

What are the symptoms?

The symptoms of hypothyroidism occur throughout the body. In adults, they usually develop slowly and are often mistaken for part of the aging process. Symptoms in adults may include:

Coarse and thinning hair.

Brittle nails.

Dry skin.

A yellowish tint to the skin.

Slow body movements and speech.

Inability to tolerate cold.

Feeling tired, sluggish, or weak.

Memory problems, depression, or difficulty concentrating.

Constipation.

Heavy or irregular menstrual periods that may last longer than 5 to 7 days.

Other, less common symptoms may include an enlarged thyroid gland (goiter), modest weight gain, a hoarse voice, muscle aches and cramps, a puffy face, and swelling of the arms, hands, legs, and feet.

How is hypothyroidism diagnosed?

A medical history and physical exam are the first steps in diagnosing hypothyroidism. If your health professional thinks you may have hypothyroidism, you will have blood tests to measure your thyroid hormones. If you have no or mild symptoms of hypothyroidism and blood tests show slightly abnormal levels of thyroid hormone, you may have mild (subclinical) hypothyroidism.

How is it treated?

Hypothyroidism is treated with thyroid hormone medication. Symptoms usually disappear within a few months after treatment begins. Most people who develop hypothyroidism need treatment for the rest of their lives.

Can I prevent it?

You cannot prevent hypothyroidism, but you can watch for signs of the disease so it can be treated promptly. Older adults, especially women older than 60, those with a strong family history of hypothyroidism, and those with Addison's disease, rheumatoid arthritis, pernicious anemia, or type 1 diabetes should be tested for hypothyroidism.

Expert groups differ on whether to recommend widespread screening for hypothyroidism. The American Thyroid Association recommends that all adults be tested beginning at age 35 and continuing every 5 years.

However, other groups say there is not enough evidence of benefit to recommend screening for everyone. But they do suggest that people who are high risk—women older than 60 and anyone with a family history of thyroid disease or who has other autoimmume diseases—may want to be screened.

Testing is indicated in adults with symptoms of hypothyroidism.

Please call and schedule an appointment if you think you have symptoms and would like to be tested.