QUESTION: I remember reading in the past that constant ringing in the ears is or could be a symptom of a physical problem. Since it did not pertain to me then, I relegated the information to a dim corner of my not-so-good-anymore memory bank. Now I have the problem. Can you fine tune my memory on this? - E.G.

ANSWER: I'll try. For millions of us, it's a buzzing, popping, ear ringing world. It's called tinnitus, the Latin for "ringing."The cause can be as mundane as earwax buildup, or it can be as significant as a hearing nerve tumor. Thus, we can never dismiss the symptoms out of hand.

Older people have the problem, although I must say we are seeing more younger ones, those who have listened to too much highly amplified rock music. In others, alcohol, nicotine and caffeine can augment the cacophony, as can drugs, like aspirin.

Some find relief through a hearing aid device that produces a masking sound to permit sleep at night. We can expect feedback mail telling how others have coped. I've painted this problem in broad strokes. Report the symptoms and let your doctor fine tune the details of your individual problem.

QUESTION: I've been waiting for a discussion of Guillain-Barre syndrome. How common is it? Does it return? - N.T.

ANSWER: We'll call it GB for short. This involves a sudden unexplained swelling of the insulation material around nerves. Nerve transmission to muscles is cut off, causing weakness.

GB symptoms usually start in the legs. Weakness spreads upward to the hips, even to the face and breathing muscles.

It all takes place over days or weeks, with recovery occurring two to four weeks later. How serious it is depends on how many muscles are involved and how extensively. Some have mild symptoms, while others require close support, as with mechanical lung ventilation.

Most recover, although I must report that 10 to 20 percent are left with residual muscle weakness, the severity of which depends again on the extent of the initial nerve/muscle disturbance.

Because the cause is unknown, no specific cure is in sight. Some speculate that certain body antibodies have attacked the nerve insulation. Perhaps a viral infection triggers that process.

GB doesn't usually recur. It is fairly common, and all ages can get it. I know of no preventive measures. And, in answer to L.Y., it is not contagious, and analysis of spinal fluid does provide evidence of the problem.

QUESTION: I need some answers. I would like to know if there is a natural diuretic for blood pressure control. I think doctors like to prescribe drugs for the money it brings. - C.C.

ANSWER: Honestly, C.C., doctors make no money from prescriptions you buy, no matter the cost.

As to a natural diuretic, I have tried to find out if there is such a thing equal in potency to prescription medicines. I can't find evidence of any such substance. There are many natural foods and drink - alcohol, caffeine, for examples - that have a diuretic effect, but I can't advise either as a kind of shortcut diuretic substitute.

Were I you, I would bite my tongue and continue with the prescription medicine my doctor gave me.

Are you bothered with ringing in the ears? Write to Dr. Donohue for a copy of booklet No. 9, "Ear Noises - Their Causes and Cures." Send your request to Dr. Donohue/No. 9, P.O. Box 830, Gibbstown, NJ 08027-9909. Enclose a long, self-addressed, stamped envelope and $2.

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.