The thyroid debate: can't lose weight? Can't sleep? Feeling irritable? Low on energy? Your thyroid may be the culprit. It's a tiny gland with a great big job

Natural Health, June, 2004 by Catherine Winters

Twenty-seven million Americans have thyroid disease--and more than eight out of 10 of them are women, reports the American Thyroid Association.

The thyroid, a butterfly-shaped gland in the neck, regulates your metabolism. Sometimes it goes awry, resulting in hypothyroidism (when it's underactive) or the more serious hyperthyroidism (when it's overactive). Whether or not to test if the thyroid is really off kilter is the subject of debate in the medical community, stirred up by a recent report in the Journal of the American Medical Association.

Checking for early signs of thyroid disease is easy, accurate and cheap: All it takes is a simple blood test. Yet the screening guidelines are all over the map. The main reason is that there's limited science available to help guide doctors.

After reviewing data on mild thyroid disease,the lAMA study concluded that there's no evidence to justify widespread thyroid screening. The focus, it said, should be on people at high risk for the disease. And because large randomized controlled clinical trials have not been conducted to see if the effects of mild thyroid failure are serious, the panel felt that there was not enough evidence to justify treatment or recommend screening for everyone.

mixed reviews

The report has its critics, especially among endocrinologists who regularly diagnose and treat thyroid disorders. "The findings do not present a consensus from various endocrine organizations, which share a different view" says Hossein Gharib, M.D., professor of medicine at the Mayo Clinic College of Medicine, in Rochester, Minn. Gharib estimates that up to 5 percent of the patients who walk through the doors of the Mayo Clinic have thyroid problems that are found by doctors there.

Discovering thyroid disease early can spare a patient needless discomfort, say many physicians. Slightly low or high thyroid levels can worsen over time, so even a mild deviation from normal is to be taken seriously.

So how do you know if you should have your thyroid tested? And if your levels are just below or above normal, should you start medication or take a wait-and-see approach?

What remains paramount, concluded the panel, is "clinical judgment and patients' preferences."

"When a patient has symptoms, there is no controversy about checking for thyroid disease," says panelist Rhoda H. Cobin, M.D., F.A.C.E., clinical professor of medicine at Mount Sinai School of Medicine in New York City.

But not everyone who has a mild thyroid problem displays symptoms. The panel agreed that aggressive case finding in people at high risk (those with family histories of the condition, or women over 50) is appropriate.

detective work Determining whether complaints like high cholesterol, hoarseness or fatigue are related to a thyroid disorder or something else entirely often requires extensive medical detective work.

"Dry skin caused by thyroid disease, for instance is indistinguishable from the dry skin you might get during the winter," says Donald Bergman, M.D., president of the American Association of Clinical Endocrinologists.

The first step to sorting all this out is a blood test that tells doctors if the pituitary gland, which drives the thyroid to produce hormones, is releasing abnormal amounts of thyroid-stimulating hormone. An enlarged thyroid, or goiter, is another red flag.

Next up is measuring the actual level of thyroid hormone. Even if that's below or above normal, the results may be inconclusive. The reading could be a fluke, caused by a temporary inflammation, so doctors typically recheck levels within a few weeks or months.

If test levels remain outside the normal range, then you clearly have mild thyroid disease. Your doctor will test for antibodies to find out if your immune system is attacking the gland. (Most thyroid disease is caused by one of two autoimmune disorders; see "Why Your Thyroid Acts Up" on page 48.) Knowing exactly what is causing your problem can help your physician plot the best course of action.

to treat or not to treat

Slightly abnormal thyroid levels can remain stable for years without causing symptoms. Nevertheless, in many people, mild thyroid disease will gradually progress. That's why some experts like to reduce potential risk by treating a patient as soon as an abnormality is detected. But Cobin notes that the lack of clinical trials leads to questions that make the issue of treatment controversial. Is the presence of mild failure itself associated with adverse health outcomes, and will treatment improve those outcomes?

Cobin says that the few small trials which evaluated symptomatic patients with very mild thyroid disease did not see much improvement in symptoms compared with subjects taking a placebo, but that physicians may want to use a "therapeutic trial" of medication to see if it helps a specific patient.

Bergman agrees to a point. "If someone has symptoms that are vague and has even minimal thyroid dysfunction, it's worth treating her to see if she feels better," he says. But someone who doesn't improve may not, in fact, be getting the right dose, he notes. "Sometimes a patient who starts medication will say, 'The fog has lifted,'" he says. Because this could be a placebo effect, Bergman monitors each patient and adjusts her dosage to make sure that her improvement is sustained long-term.