DEAR DR. DONOHUE: I have a problem that I don’t understand, and my doctor is no help.

My feet and ankles, and sometimes my legs, swell. I am 79, and the Lord has blessed me with good health except for high blood pressure. (I have attached a list of the medicines I take.) Is this just an old-age thing, or should I be concerned? – M.K.

ANSWER: When the feet, ankles and legs swell, it’s edema (uh-DEE-muh). The causes for it are many. It comes from heart failure, liver disease and kidney malfunction. It would be hard to miss such causes because they have other, even more conspicuous signs.

Some medicines cause edema. One of your four blood pressure medicines – Norvasc – can, at times, cause such swelling. Speak with your doctor about this possibility, and see if a change or a reduction in the number of your blood pressure medicines can be made.

This kind of swelling also comes from innocent conditions. Sitting for long periods with the feet dangling down allows gravity to draw fluid from the circulation, and the fluid oozes into the tissues of the legs and feet.

Try a few self-help remedies for edema. Don’t sit for long times without getting up and moving around. While sitting, prop your legs up on the seat of a kitchen chair. During the day, take three or four 15- to 30-minute breaks when you lie down with your legs propped up to a level higher than your heart. Cut way back on salt and salty foods to prevent your body from retaining too much fluid (and for your blood pressure). Elastic compression stockings can keep fluid in the circulation and out of the leg, ankle and foot tissues.

The booklet on edema and lymphedema discusses this kind of swelling in detail and provides tips on its management. Readers can obtain a copy by writing: Dr. Donohue – No 106, Box 536475, Orlando, FL 32853-6475. Enclose a check or money order (no cash) for $4.75/$6.75 Can. with the recipient’s printed name and address. Please allow four weeks for delivery.

DEAR DR. DONOHUE: My wife has cuts in the corners of her mouth. They’re red, and they hurt. This has been going on for some time, and no one can seem to help. It makes her lips and mouth burn when she eats. What can she do? – M.Z.

ANSWER: That has to be angular cheilitis (key-LIGHT-iss), a common condition in older people. Cracks and fissures form in the corners of the mouth where the upper and lower lips meet. Saliva pools there and provides fertile soil for fungi and yeasts, and possibly staph. Ill-fitting dentures can push the upper and lower jaw out of line and bring about corner-of-the-mouth pockets that retain saliva. If she has dentures, take your wife to the dentist.

You can also try home remedies. Dab some anticandida (candida is the yeast often involved) cream on the corners of your wife’s mouth, and reapply it as it specifies on the tube. Your pharmacist can direct you to such a product. Leave the cream on for a few hours, then wipe it off and put some cortisone cream on the sites. That too is available in drugstores. Leave the cortisone cream on for a couple of hours, wipe it off and reapply the anticandida cream Repeat this process at least twice a day, preferably three times.

When the cracks heal, your wife should begin daily use of a lip balm such as Chapstick. It’s one of many brands.

If you’re making no progress on your own, your doctor can prescribe medicines that are stronger than the ones on public shelves.

DEAR DR. DONOHUE: I sent you a letter but have seen no answers. I have a new question. If the only dumb question is an unasked question (a quotation from you), what is an unanswered question? – M.N.

ANSWER: It’s an unpardonable breach of etiquette. I can give you a few reasons why I can’t answer everyone’s questions: I don’t know the answer and can’t find anyone who does; the question was asked and answered recently; or the circumstances surrounding the question make it one more appropriately answered by a doctor in the privacy of a medical office.

DEAR DR. DONOHUE: I have had cellulitis, a bacterial infection of the skin, on my left arm more than once. I also have lymphedema of that arm. I had my left breast removed for cancer, and I understand that the lymphedema is related to this. What can I do for both? – Anon.

ANSWER: Lymphedema is swelling of an arm or leg due to a disruption of lymph vessels and lymph nodes. Lymph is fluid that oozes out of the circulation to bathe body cells. Lymph vessels vacuum up that fluid and return it to the circulation. On its way back, the fluid passes through lymph nodes, where germs and foreign material are filtered out.

After extensive breast surgery during which lymph channels and lymph nodes have to be removed, the return of lymph fluid to the general circulation is greatly disturbed, and the arm often becomes congested with fluid – it swells. That makes the skin of the arm susceptible to infection – cellulitis.

If you can get the fluid out of the arm, you’ll solve both the swelling and the cellulitis. Therapists trained in “decongestive” massage can knead the fluid out of the arm. They use light massage strokes to achieve that. Pneumatic pumps can also push fluid out of a swollen arm.

Compression sleeves, which firmly and constantly squeeze the arm, can prevent the fluid from returning. The same therapists who are skilled in decongestive massage can teach their patients exercises that promote fluid drainage out of the arm.

Your doctor or local hospital can put you in touch with one of these health care workers. Or you can contact the National Lymphedema Network, a foundation that serves people with this condition. The foundation’s toll-free number is 1-800-541-3259, and its Web site is www .lymphnet.org.