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. 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.
The review panel found that treating a person with mild thyroid disease didn't have a clear advantage over waiting until the dysfunction reached a more critical level. For someone who has no symptoms and isn't thrilled about popping pills, this may come as good news. Yet once a problem has been identified, it's vital to continue to get regular thyroid blood tests. For when thyroid-hormone levels creep outside the normal range or symptoms start to appear, medication is a must. "If someone has too much or too little thyroid hormone, there are going to be repercussions for every tissue and organ in the body," declares Cobin.
The scenario changes slightly for thyroid-related autoimmune disorders. "Evidence indicates that people with these kinds of disorders are likely to progress to overt hypothyroidism within two to 10 years," says Leonard Wartofsky, M.D., chairman of the department of medicine at Washington Hospital Center in Washington, D.C. If a patient doesn't want to go on drugs, Wartofsky repeats screening tests every six months and prescribes medication at the first hint that the disease has begun to progress.