QUESTION: I am 30 years old and suffer from anxiety. What causes anxiety? Besides taking medicine, what can be done to control it? - D.M.

ANSWER: Some say anxiety results from thoughts and feelings repressed within the subconscious, that they are so frightful to us that we dread to think of them objectively, so we bury them in that hidden recess of the mind. Others say that anxiety results from an imbalance of nerve chemicals that regulate mood and feeling. Perhaps there's a bit of both factors at play.Treating anxiety depends on which view you take. Some find relief from medication (such as the one you mention in another part of your note). Others improve once those covert thoughts come into the open by way of psychiatric therapy with a trained professional.

Meditation and relaxation techniques offer a way out of anxiety for some sufferers. Along that line, I can recommend a helpful paperback to you. It's "The Relaxation Response," by Herbert Benson, published by Avon (paperback).

QUESTION: I am very concerned about my husband. He took a pretty bad fall a couple of weeks ago. He got a couple of bruises, but felt fine. He didn't think he needed a doctor, but now he can't sleep. His right arm keeps going numb, and his neck hurts. Please help. Does he need a doctor? Will he be all right? He works with heavy material on the job. - Mrs. K.G.

ANSWER: Yes, he needs to see a doctor. Persistent neck pain along with numbness can spell serious problems. He may have fractured one of his neck vertebrae. Don't dally any further.

QUESTION: When I have told my friends about adult polycystic kidney disease, they don't seem to know what it is. I was diagnosed with APKD about four years ago. I too had a hard time finding out about the problem until I attended a couple of meetings of the local support group. Would you please explain this disease, so the public will be more informed? - D.A.E.

ANSWER: Glad to. Adult polycystic kidney disease is an inherited illness, one that doesn't show itself until later years. Often the first signs of it are bloody urine, pain in the back and high blood pressure. The kidneys may enlarge, sometimes to relatively enormous size.

We know for sure that a gene is responsible for APKD, but how it produces the cysts is a mystery. More research is being done to settle such questions, you can be sure. For now, taking ultrasound pictures of the kidneys is an excellent way to detect the cystic changes.

The prognosis with APKD varies. Sometimes it can be handled by simply controlling the high blood pressure, which is almost always present. If the cysts begin disrupting normal kidney function, then a kidney transplant may be needed.

QUESTION: I have a suggestion for C.H., whose husband had trouble falling asleep during the daytime. My husband was on the graveyard shift for 10 years, and believe me, it was well named. Kids, dogs, cars and various other daytime sounds kept him awake. One day, I bought a little $15 fan, darkened his room and turned the fan on medium speed. It blocked out all the noises. He never had trouble sleeping again. - Mrs. L.L.H.

ANSWER: Thanks for the idea. Many graveyard shift workers will welcome your suggestions, I'm sure.

QUESTION: Why is bulimia, the purposeful vomiting of food to stay slim, so damaging to the teeth? I know of a girl who paid $2,000 for teeth repair because of this. - S.B.

ANSWER: When one vomits, not only food is expelled, but stomach juices, which are quite acid. That acid can destroy your teeth. The lesson learned here is that bulimia is far from being a harmless practice. If a person suffers from it, he or she should consult a doctor to get needed help.

Premenstrual distress. Menstrual cramps. These problems plague millions of women. Dr. Donohue has a booklet that discusses diagnosis and treatment and explains precise causes. For a copy of "PMS and Painful Menstrual Periods," send $2 and a stamped, self-addressed envelope to Dr. Donohue/No. 36, P.O. Box 830, Gibbstown, NJ 08027-9909.

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.