Do you need a thyroid test? From the November 2015 Harvard Women's Health Watch

Published: November, 2015

Many people know of the common symptoms of low thyroid hormone (also known as hypothyroidism) — fatigue, fuzzy-headedness, weight gain, cold hands, and dry skin. But many people who find their cholesterol levels and weight are creeping up are more likely to blame their diet and exercise regimen instead of their thyroid, especially if they don't have any of the other symptoms.

Thyroid hormone plays a major role in regulating metabolism — the process by which body cells convert nutrients into energy — and thereby helps regulate body temperature, heart rate, and even brain function. So when thyroid hormone levels fall, the body slows. "Symptoms are often nonspecific, and since women over 60 generally have more of these nonspecific symptoms, their doctors may not think to test for hypothyroidism," says endocrinologist Dr. Jeffrey Garber, associate professor of medicine at Harvard Medical School and author of The Harvard Medical School Guide to Overcoming Thyroid Problems.

Women of all ages are more likely than men to have low thyroid hormone levels. By some estimates, almost a quarter of women over 60 have inadequate levels. However, many of their symptoms are attributed to other conditions or written off as a consequence of aging.

The only way to tell if a person's thyroid hormone levels are too low is through a blood test. However, as many as 60% of people with low thyroid hormone aren't aware anything is wrong because they haven't been tested. The U.S. Preventive Services Task Force (USPSTF) doesn't recommend routine thyroid screening because it hasn't found sufficient evidence that testing thyroid hormone levels in large groups of people without symptoms is cost-effective.

Dr. Garber agrees, and suggests a different approach — testing asymptomatic people who are most likely to develop the disease and benefit from treatment. Treating people in the earliest stages of hypothyroidism with synthetic thyroid hormone reduces the likelihood that they will develop more serious problems in the future, especially cardiovascular disease. In fact, low thyroid hormone can often be the cause of high cholesterol, and treatment with thyroid hormone may make statin therapy unnecessary.

Read the full-length article: "Do you need a thyroid test?"

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