DEAR DR. DONOHUE: My daughter has been diagnosed with fibromyalgia. Could you give me some information on it? She walks on a treadmill daily and works out twice a week. She has been using artificial sweeteners for years and has been on birth control pills for 10 years. Would these have any bearing on the condition? – P.W.

ANSWER: Fibromyalgia is an enigma. Its cause is unknown, and its treatment is challenging. There is no substantial evidence to implicate either birth control pills or artificial sweeteners in its origin.

Symptoms are bodywide muscle pain along with muscle stiffness and profound exhaustion. Neck, shoulder and hip muscles are almost invariably involved, and their involvement makes carrying out the most routine daily tasks difficult.

In addition, sleep disturbance is common. People with fibromyalgia never waken refreshed. They often find it impossible to concentrate, and their memory might not be as retentive as it once was.

There is no lab test that provides proof of this illness. There is no X-ray or scan that can support the diagnosis, and that makes fibromyalgia an elusive condition.

However, tender points help. Tender points are 18 specific body sites where moderate pressure from the doctor’s examining thumb produces pain far out of proportion to the pressure applied. Finding 11 of the 18 tender points puts the diagnosis on firmer ground.

Essential to the diagnosis is the elimination of any illness that has symptoms similar to those of fibromyalgia. Rheumatoid arthritis and lupus are two such illnesses, so lab tests are done to exclude those maladies.

Amitriptyline, an antidepressant, is often prescribed – not for its action against depression, but for its ability to restore sound sleep. Muscle relaxants and seizure medicines such as gabapentin and topiramate are also employed. An exercise program is an essential component of therapy.

The fibromyalgia booklet describes this illness and its treatment in greater detail. Readers can obtain a copy by writing: Dr. Donohue – No. 305, Box 536475, Orlando, FL 32853-6475. Enclose a check or money order (no cash) for $4.50 U.S./$6.50 Can. with the recipient’s printed name and address. Please allow four weeks for delivery.

DEAR DR. DONOHUE: I have an 85-year-old friend who takes a cod liver oil pill every day – no other medicine. How healthy is it? Does it keep arteries free of obstructing buildup and reduce the chances for a stroke or heart attack? – J.Q.

ANSWER: Cod liver oil contains omega-3 fatty acids that pay big dividends to the heart and blood vessels, as do all fish oils. They lower blood triglycerides – fats that work in concert with cholesterol to plug arteries. They calm heart muscle and prevent the development of potentially fatal heartbeat rhythms. They stop blood platelets (clot-forming blood cells) from sticking to each other, another factor instrumental in keeping blood flowing freely through all arteries in general and heart and brain arteries in particular. Cod liver oil is healthy.

It’s also chock-full of vitamins A and D – so chock-full that users should pay attention to how much they are taking. The daily vitamin D requirement for adults ranges between 400 and 800 IU. It should not exceed 2,000 IU. An adult woman’s daily vitamin A requirement is 2,300 IU, and a man’s, 3,000. People should not go much beyond that amount on a daily basis. Too much vitamin A can produce osteoporosis.

Your friend’s single pill is not likely to have toxic levels in it.

DEAR DR. DONOHUE: A mosquito can transmit malaria and West Nile fever. Why can’t a mosquito transmit the AIDS virus? – S.Y.

ANSWER: If you consider the entire catalog of germs, you find that mosquitoes spread only a very few. Only a handful of germs can survive in the mosquito. The AIDS virus is not one of them.

DEAR DR. DONOHUE: Recently my son, age 39, was diagnosed with multiple sclerosis. He was hospitalized and given steroids. The steroids gave him a great deal of stomach discomfort. Do you have some advice as to what might give him some relief from his symptoms? He has severe weakness, unsteadiness, double vision and face numbness. – H.R.

ANSWER: The “sclerosis” of multiple sclerosis refers to scars scattered throughout the brain and spinal cord. They’re due to inflammation that comes from an immune attack on nerves and their insulating material. What brings on the attack is a question still begging for an answer.

Symptoms of MS can come on abruptly or slowly and imperceptibly. Involvement of the optic nerve, a common early symptom, dims vision and can cause a loss of color perception. Double vision results from inflammation in a part of the brain that coordinates eye movement. An attack in brain areas controlling arm and leg motion leads to clumsiness, weakness and trouble walking. Peculiar sensations, numbness and sometimes pain can arise.

The most common kind of MS is called relapsing/remitting, where an attack continues for days or weeks and is then followed by recovery in the ensuing weeks or months. As time progresses, however, symptoms tend to remain. Newer medicines have brought great hope to MS patients.

Prednisone, one of the cortisone steroid drugs, is often used to control the inflammation of an acute attack. It can upset the stomach, and if it does, there are medicines, such as ranitidine, that can diminish the stomach discomfort. With drugs that can modify the basic immunologic disturbance, doors have opened to reduce the number of relapses and the development of new scars. Avonex, Rebif, Betaseron and Copaxone are some of their names.

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.