DEAR DR. DONOHUE: I took two full courses of antibiotics for what was supposedly a sore throat. Then I consulted another doctor. Guess what: I didn’t have a sore throat. I had thyroiditis. How and why did I get this? Does it permanently hurt the gland? – Anon.

ANSWER: To get oriented anatomically: If readers put their hands around the lower neck as though they were trying to choke themselves, they have located the thyroid gland. It’s a gland of many functions, but its chief purpose is to keep body cells and organs running at peak efficiency. Without thyroid hormone, body processes slow and eventually stop.

Thyroiditis is gland inflammation. What causes the inflammation is disputed, but it often occurs after a simple viral infection, like a common cold.

Pain in the lower neck, in the region of the gland, is a prominent symptom. Or swallowing can be painful, and that gives rises to confusion and a misdiagnosis of sore throat. Pain can also radiate to one or both ears.

Furthermore, the gland is swollen and tender to the touch. People often have a fever. Their white blood cell count rises, as does their sedimentation rate. The latter is a blood test that indicates inflammation is taking place somewhere in the body.

When all of the above information is in place, the diagnosis is relatively simple. When only some of the symptoms and signs are present, the condition can easily be mislabeled.

How and why you got it are questions that are not likely ever to be answered. It just happens.

For most people, everything quiets down on its own, with aspirin being the only medicine needed. For severe symptoms, prednisone (a cortisone drug) quickly suppresses inflammation. Rarely, if ever, does this kind of thyroiditis cause permanent gland damage.

The thyroid gland pamphlet answers questions on the most common kinds of thyroid disorders. Readers can obtain a copy by writing: Dr. Donohue – No. 401, Box 536475, Orlando, FL 32853-6475. Enclose a check or money order (no cash) for $4.50 U.S./$6.50 Can. with the recipient’s printed name and address. Please allow four weeks for delivery.

DEAR DR. DONOHUE: My 22-year-old nephew was hospitalized for myocarditis. He is out of the hospital now. My sister said he had to be treated for a failing heart when he was in the hospital. What does this mean for his future? – C.S.

ANSWER: “Itis” always indicates inflammation, and “myocardio” indicates heart muscle. Your nephew had heart muscle inflammation, and the usual cause is a viral infection.

Many viral myocarditis patients recover completely. However, when the infection so weakens the heart that it loses its pumping power and suffers heart failure, predictions about the future are less sanguine. Some of these patients are left with a permanently damaged heart. Your nephew appears to have regained his health. If he is not now under treatment for heart failure, then his chances for full recovery are excellent.

There are no medicines that can treat the viral infections. There are many medicines that can restore vigor to a heart weakened by a viral infection.

DEAR DR. DONOHUE: I am a 52-year-old lady in good health except for one problem. My left nipple has a green discharge when I squeeze it. I have had mammograms and seen many doctors, and all comes out well, but I am still uneasy. Could this be cancer? – M.K.

ANSWER: Nipple discharges always turn a woman’s mind to cancer. A clear or bloody discharge associated with a breast lump raises the suspicion for cancer. A green discharge is associated with milk duct ectasia, an inflammation of the duct or ducts, which enlarge and become partially blocked. This is not cancer and does not become cancer. Your doctors and your mammograms tell you all is well. Believe them, and stop squeezing that nipple.

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.