QUESTION: Our 40-year-old uncle has terrible times with his asthma, mostly at night. He wakes up with attacks and worries us so when he is visiting. I am wondering if his medicine is helping him at all. Please comment, especially about the night problem. Thanks. - Mrs. T.L.L.

ANSWER: Asthma has many triggers. The nighttime episodes raise a couple of possibilities. One is of stomach acid reflux, that is a splashing up of stomach acid into the lower esophagus at night when he is recumbent. That can easily be aspirated into the respiratory area to trigger an asthmatic response through constriction of the breathing tubes.Another possibility is his medicine. Sometimes, the doctor can prescribe a longer-lasting type drug to take the asthmatic through the night hours. You can readily check the acid idea by elevating the head of his bed at night to discourage reflux. If there is no help, you should have the idea of the medicine looked into.

QUESTION: I have had a protrusion (soft) on my elbow for six months. This is the size of a golf ball. It is not painful, just uncomfortable. I have ignored it. I am told it should go away on its own. I am still waiting. There is no lessening of size. Have you any suggestion? - M.E.

ANSWER; A soft golf ball size swelling at the elbow usually suggests bursitis, the elbow equivalent of housemaid's knee. Ice packs and aspirin should have brought it down by now. You may need to have the swelling fluid withdrawn with a syringe. Or you may benefit by having cortisone instilled directly into the inflamed bursa. Once the inflammation is ended, the swelling should subside. I would have a doctor look at this.

FOR MRS. W.M. - Coumadin is a blood-thinning drug. It is given for many medical reasons, and you don't indicate in your letter why you have been put on it. But that is not the important thing here. The important point is that before your dental work, you have to check with the prescribing doctor, because you may have to be taken off it temporarily until the dental work (removal) is over. And you should certainly tell the dentist you are on the drug. You can go back on the Coumadin as soon as any bleeding possibility is past.

QUESTION: Is it true that exercise has to be of a significant intensity in order to have it lower blood cholesterol? - O.Q.

ANSWER: One study says intensity of exercise is a factor in raising the level of the good kind of cholesterol (HDL) and lowering of the bad kind (LDL). Some say that the intensity should be such as to raise the pulse rate to 75 percent of the person's personal maximum rate, and your doctor can tell you what that is.

Certainly, not all exercisers can or should attain that 75 percent level of max pulse rate. To be honest, studies have not been conclusive regarding the whole matter of cholesterol improvement with exercise. But it seems to me that the basic benefits to health from your personal exercise capability would be worthwhile with or without the cholesterol consideration.

FOR MRS. J.O - The hormones get into the blood through skin patches as effectively as from the pills. Such skin patches have been helpful in endometriosis.

In response to reader requests, Dr. Donohue's publisher now has a complete listing of all the booklets on various medical problems. Readers wishing this free list can send their request to Dr. Donohue/list, P.O. Box 830, Gibbstown, NJ 08027-9909. Enclose a stamped, self-addressed envelope.

Dr. Donohue welcomes reader mail but regrets that, due to the tremendous volume received daily, he is unable to answer individual letters. Readers' questions are incorporated in his column whenever possible.