DEAR DR. DONOHUE: My son, 50, has been diagnosed with Graves’ disease. Will you define the condition and its treatment? I am very concerned for him. – J.C.

ANSWER: Graves’ disease is the No. 1 cause of an overactive thyroid gland – hyperthyroidism. It happens because the immune system, for reasons not clear, makes antibodies that stimulate the thyroid gland. Antibodies usually are used to fight germs. Not in this case. These special antibodies prod the thyroid gland into overproduction of thyroid hormone.

In huge quantities, thyroid hormone throws the body into high gear. The heart races even when the person is sitting quietly. Hyperthyroid people are warm when others around them are comfortable or cold. They lose weight in spite of eating large amounts of food. Hand tremors often appear. Eyelids are always wide apart, as though these people are constantly staring. Women’s periods lessen and disappear. A goiter is seen in the lower neck. A goiter is simply an enlarged thyroid gland.

The diagnosis of the illness is easy when a person has many signs and symptoms. It is difficult if there are only a few mild ones. Lab tests can detect the level of thyroid hormone, and that helps clinch the diagnosis.

Graves’ disease is a serious illness. In the days before there was adequate treatment, 10 percent to 30 percent of Graves’ patients died. Now, with modern treatment, death is almost unheard of, and treatment cures most.

Treatment consists in taking medicines that stop thyroid hormone production, taking a radioactive pill that puts the gland out of commission or having the gland surgically removed. In North America, the radioactive pill (radioactive iodine) is the treatment most often chosen. Iodine heads for the thyroid gland like iron goes to a magnet. After treatment is completed, the person has to take thyroid hormone by mouth, but that’s not a huge deal. It amounts to taking one tablet a day.

DEAR DR. DONOHUE: Through the years, I have been troubled with restless leg syndrome. One day it struck me that I had the worst symptoms on days when I drank little water. That night, I had symptoms, so I drank 10 ounces of water. The symptoms disappeared. That was seven months ago, and since then I make sure to have plenty of water before bed. I have not had a recurrence of restless legs. I thought I might have to get up often during the night to go to the bathroom, but this has not happened to me. I hope it works for others. – D.M.

ANSWER: So do I, D.M. If it doesn’t, I’ll hear about it.

For more conventional approaches to restless leg syndrome and nighttime leg cramps, the booklet on those topics covers most of the standard treatments. Readers can order a copy by writing: Dr. Donohue – No. 306, Box 536475, Orlando, FL 32853-6475. Enclose a check or money order (no cash) for $4.75 U.S./$6 Can. with the recipient’s printed name and address. Please allow four weeks for delivery.

DEAR DR. DONOHUE: My 48-year-old daughter has keratoconus. What are the options to prevent eventual blindness? Is a corneal transplant a viable option? What is its success rate? How long does it last? – E.W.

ANSWER: Keratoconus has to do with the eye’s cornea. The cornea is the transparent cover in front of the pupil. In keratoconus, it thins and forms a conelike bulge that distorts vision.

If the bulge is not extreme, glasses or contact lenses can compensate for the distortion. When lenses no longer compensate for the amount of bulge, then a corneal transplant is the answer.

Corneal transplants are the most successful of all transplants. Ophthalmologists obtain good results in more than 90 percent of patients. The transplant lasts a lifetime.

You and your daughter would greatly benefit by contacting the National Keratoconus Foundation at 800-521-2524 or on the Internet at www.nkcf.org. The foundation provides information and allays the natural fear that all keratoconus patients have.

Dr. Donohue regrets that he is unable to answer individual letters, but he will incorporate them in his column whenever possible. Readers may write him or request an order form of available health newsletters at P.O. Box 536475, Orlando, FL 32853-6475. Readers may also order health newsletters from www.rbmamall.com