Borderline Hypothyroidism Needs Attention, Medication

Q:  I recently was diagnosed with hypothyroidism. I am a 48-year-old male who keeps an active lifestyle with exercise, skiing, tennis and other sports. I had a blood test and the TSH scores are high (three different ones over three years). My questions are these: 1) Can exercise, since it lowers one's metabolic rate, lower thyroid production? 2) Is there any danger in not taking the medication Levoxyl? I really have very few symptoms, if any. I haven't started taking it yet because I am worried about taking a lifetime med and side effects such as heart arrhythmia or hair loss. If I do have hypothyroidism, I believe it to be borderline. Can you discuss this condition in a column?

A:  Thyroid disease is quite common, affecting millions of Americans each year, and often goes undiagnosed for several months. Hypothyroidism is a condition where your thyroid is not producing enough thyroid hormone. The usual cause is your own body attacking the thyroid gland, what is called an autoimmune reaction. Diagnosis of hypothyroidism is confirmed with the TSH (thyroid stimulating hormone) blood test. Levels above 5 are abnormal - 5-10 is early or borderline hypothyroidism, and levels above 10 usually indicate hypothyroidism.

Once in a while people have a transient "thyroiditis," in which the hypothyroidism only lasts for a few months before the gland starts producing hormone again. This can be seen in women shortly after delivering a baby. One of my patients who had a child six months ago noticed that she was losing large amounts of hair by the handful. Her TSH was 82! This has subsided now that she is taking thyroid replacement.

Let's talk briefly about the signs of hypothyroidism, since these are the symptoms that should alert you and your doctor to pursue this easily correctable condition. You should keep in mind that not all people are going to experience all of the following. In fact, most people experience only a few of the possible manifestations of clinical hypothyroidism.

Signs and symptoms include cold intolerance, lethargy and mental fatigue, weight gain and constipation. Severe hypothyroidism that goes untreated for an extended period of time can lead to hair loss. As you can see, hypothyroidism can mimic several other conditions, including depression and even male-pattern baldness.

You asked about exercise and thyroid medication. Exercise actually increases your basal metabolic rate, but it has no effect on thyroid function or thyroid hormone replacement. The side effects of thyroxine (Levoxyl or Synthroid are two brand names) are very minimal, and your main concern should be keeping your TSH within acceptable limits as established by your physician.

Understand that too-high doses of thyroxine could potentially cause an arrhythmia, so it is important to let your physician know if you experience any palpitations or heart racing. Too much thyroxine also can increase your risk of osteoporosis.

Once a person is diagnosed with hypothyroidism, the treatment is a lifetime of thyroid replacement medication - usually just one pill per day. So what happens if you just don't take the medication? Even though you feel fine now, symptoms probably will develop and worsen over time. You will most likely be surprised at how much better you feel once you start taking Levoxyl.

Samer Choksi, a senior medical student at the Medical College of Wisconsin, helped me with this answer because he has a great personal interest in thyroid disease. He was diagnosed with hypothyroidism himself in his 20s.

"Dear Doctor" is a compilation of patient questions answered by doctors from the Medical College of Wisconsin.