June 14, 2006

AMARILLO – About 27 million Americans have overactive or underactive thyroid glands, said Andrew B. Crocker, Extension gerontology health specialist. More than half of those are undiagnosed.

Of those diagnosed, 80 percent are women. Underactive thyroid is an age-related condition: by 60, as many as 17 percent of women and 9 percent of men are affected.

"In short, if the thyroid does not work properly, neither do you," Crocker said. "If left untreated, thyroid disease may cause elevated cholesterol levels and subsequent heart disease, infertility, muscle weakness, osteoporosis and, in extreme cases, coma or death, among other things."

Part of the body's endocrine system, the thyroid gland is located just below the Adam's apple, he said. The thyroid hormone influences nearly every organ, tissue and cell in the body.

The most common diseases of the thyroid are hyperthyroidism (overactive) and hypothyroidism (underactive), Crocker said. The gland's activity level is related to the amount of hormone it produces.

Sometimes the thyroid can become enlarged, he said. An enlarged thyroid gland is often called a ‘goiter,' he said. Patients also may develop lumps or masses in their thyroid glands, which may appear gradually or very rapidly.

A health care professional should evaluate all lumps or masses associated with the thyroid gland.

Symptoms of hyperthyroidism are: heat intolerance, sweating, weight loss, altered appetite, frequent bowel movements, changes in vision, fatigue and muscle weakness, sleep disturbances and tremors.

Common symptoms of hypothyroidism are: fatigue, forgetfulness, depression, dry coarse hair, mood swings, weight gain, hoarse voice, dry coarse skin and constipation.

While thyroid disorders are easy to diagnose, signs and symptoms may be overlooked because they resemble so many other conditions, Crocker said.

The diagnosis of a thyroid abnormality is made through physical examination and medical history, he said. Specifically, a health provider will examine the neck and ask the patient to lift up his or her chin to make the thyroid gland more prominent.

"You may be asked to swallow during the examination, which helps to feel the thyroid and any mass that may be in it," Crocker said.

Other tests a health provider may order include:

– An ultrasound examination of the neck and thyroid.

– Blood tests to determine the level of thyroid hormone in the blood.

– A radioactive thyroid scan

"If a lump in your thyroid is diagnosed, your health provider may recommend a fine needle aspiration biopsy," Crocker said. "This is a safe, relatively painless procedure. This test gives the health provider more information on the nature of the lump in your thyroid gland and specifically will help to differentiate a benign from a malignant thyroid mass."

Abnormalities of thyroid function are usually treated with prescription medications, he said. Insufficient production of thyroid hormone may require a supplement.

Hyperthyroidism is treated mostly by medicine, but occasionally it may require the surgical removal or inactivation of the thyroid gland, Crocker said.

"It is a good idea to have your health provider check the thyroid hormone level in your blood on your next office visit," he said. "If he or she does not mention it specifically, be sure to ask about it."

More information can be found from the American Thyroid Association: http://www.thyroid.org .