DEAR DR. DONOHUE: It would be a real service to the public if you discussed multiple myeloma. It is a serious cancer, and few people, other than those affected by it, know about it. — I.M.

ANSWER: Multiple myeloma is a bone marrow cancer. The bone marrow is where all blood cells are made. “Myel” refers to bone marrow; “oma” to cancer; and “multiple” indicates that the process goes on in many bones. This cancer is composed of a special kind of blood cell called the plasma cell.

With the extravagant multiplication and growth of plasma cells in the marrow, a number of dire consequences result. One is a depressed production of red cells, and that leads to anemia. Fatigue and breathlessness are signs of anemia. Overcrowding of the marrow disrupts bone health and leads to bone pain and bone breaks. That’s why myeloma patients frequently have back and chest pain. Back bones might collapse to make a patient lose several inches of height. Plasma cells manufacture a protein that damages the kidneys. Renal failure, therefore, often is a consequence of this cancer.

The diagnosis of myeloma is made through the patient’s symptoms, by finding the peculiar myeloma protein in blood and urine, and by examining a specimen from the bone marrow with a microscope.

No cure medicine for myeloma exists, but there are many medicines that have made significant contributions to the way it’s managed. I can’t mention all their names. But I will say something about a treatment used for some myeloma patients. High doses of chemotherapy drugs are given to kill off as many plasma cells as possible. This is then followed by infusing the patient with stem cells that have been collected from his own marrow and blood before chemotherapy. Those cells repopulate the marrow with normal cells. This specialized treatment is a treatment used for only a group of myeloma patients, not for every myeloma patient.

DEAR DR. DONOHUE: I have HIV. I have been taking medicines for it since the end of 2009. I was diagnosed in 2006. I take three medicines for it. I have enclosed their names for you. Do they sound like the proper medicines? My CD4 cell count is 970, and virus cannot be detected in my blood. If I were to take these meds improperly, what would be the result? Say I take too many of one or miss one on occasion. — L.E.

ANSWER: HIV is the human immunodeficiency virus, the cause of AIDS. This virus devastates the body’s immune defenses and makes infected people the target of serious infections and some cancers. One virus target is the CD4 cell, one of the immune defense cells. These cells plummet with active infection. Your CD4 count is normal. That’s one of the best signs that you are taking the correct medicines. Add to that the fact that no virus is detectable in your blood. That’s added evidence that your medicines are doing the job.

Improperly taking your medicines could cause a resurgence of virus in your blood and a drop in your CD4 count. Or it could spawn resistance in your virus to your drugs. Missing a dose on occasion isn’t going to upset your control, but you have to follow your dosing schedule as faithfully as is humanly possible in order to keep the virus suppressed.

DEAR DR. DONOHUE: For many years I have tried to find a cure for my wife’s tremendous belching. I have taken her to several clinics and to many specialists. Can you come up with an answer? — I.G.

ANSWER: Your wife has been to some of the most prestigious medical centers in this country. I can’t add to what she was told there. I can explain what causes belching, and that might help her. A belch releases gas from the stomach. The gas is mostly swallowed air. Slow, deliberate chewing of small portions cuts down on air swallowing. She should not drink any carbonated beverages. Chewing gum encourages air swallowing. I realize these sound like banalities, but even banalities can help. Perhaps readers can come to our aid with other thoughts.

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. Readers may also order health newsletters from