DEAR DR. DONOHUE: I have been diagnosed with fibromyalgia. The problem is that people look at me and think I don’t look sick, so how could I feel so bad. My muscles hurt. I’m so tired that by noon I am exhausted. Please explain fibromyalgia. Maybe the public will see that I may look OK on the outside but I am screaming with pain on the inside. — M.S.

ANSWER: Fibromyalgia, like chronic fatigue syndrome, has no outward signs of illness. And also like chronic fatigue syndrome, its cause remains a mystery, making treatment difficult. People with this condition hurt all over and are engulfed by energy-sapping fatigue. It is like chronic fatigue in many aspects. One feature unique to fibromyalgia is tender points, points on the body where the examining finger of the doctor elicits pain far out of proportion to the pressure the doctor applies. Each side of the body has nine such sites, for a total of 18 tender points. Identifying 11 of these areas helps secure the diagnosis.

Like chronic fatigue, fibromyalgia has no blood test, X-ray or scan that proves the diagnosis.

Fatigue is a prominent fibromyalgia symptom. Waking up as tired as when a person went to bed is another typical sign of this illness. Anxiety and clouded thinking, which some call fibro fog, are part of the picture.

As with chronic fatigue, an active exercise program is important. Inactivity deconditions muscles, which amplifies the weakness and pain that the illness causes. Water exercises often are well-tolerated.

As far as medicines, Cymbalta, Savella and Lyrica are treatments approved for this illness by the Food and Drug Administration.

DEAR DR. DONOHUE: In July I was diagnosed with Wenckebach, type 1, second degree AV block. An EKG showed it. I also had a stress test and an echocardiogram and 24-hour Holter monitoring.

I was told that no treatment or medicine is necessary.

Does Wenckebach always progress to type 2 AV block? Will I need a pacemaker? — E.M.

ANSWER: Every heartbeat starts out as an electric blip, generated by a small island of specialized heart cells called the SA node. The structure is in the upper-right heart chamber, the right atrium. The electric signal travels down to another node of cells, called the AV node. Here, its speed is slightly slowed. With second-degree AV block, Wenckebach (WIN-key-bok) Mobitz type 1, the EKG shows a progressive slowing of the electric signal in the AV node until one transmission is completely blocked — the heart misses a beat. Almost never is a patient aware of what happened. Rarely does this condition progress to a more serious situation like type 2 AV block. A pacemaker is almost never needed. It’s a slight abnormality of the heartbeat found in many highly conditioned athletes.

The booklet on heartbeat abnormalities deals with the more common ones like atrial fibrillation. Readers can order a copy by writing: Dr. Donohue — No. 107, Box 536475, Orlando, FL 32853-6475. Enclose a check or money order (no cash) for $4.75 U.S./$6 Can. with the recipient’s printed name and address. Please allow four weeks for delivery.

DEAR DR. DONOHUE: I have a lot of problems with sinus infections. I had sinus surgery 10 years ago. The ear, nose and throat doctor said I had pockets of infections in them. Now I am having problems again. Avelox is the only antibiotic that works. The most recent infection is not responding to Avelox as in the past. Can you give me any advice? — Anon.

ANSWER: It’s time that the ear, nose and throat doctor explored your sinuses again. These doctors use a slender scope that allows them to inspect the sinuses and take a sample of the lining tissue. Part of the sample can be cultured for identification of the offending germ

With the germ identified, it can be tested for its sensitivity to a panel of antibiotics.

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 www.rbmamall.com.