DEAR DR. DONOHUE: I am a 68-year-old male in very good health. I work out one hour a day, six days a week. I play golf, lift weights and use a NordicTrack.

I have pain in my right shoulder so intense that I don’t dare sleep on that side. It often wakens me from sleep. During the day it hurts but is tolerable. I have gotten three different diagnoses — bursitis, arthritis and tendinitis. How do I alleviate this pain? — W.S.

ANSWER: The shoulder is the body’s most versatile joint. No other joint has a range of motion like it has. Its versatility, however, is one factor in its frequent injury. The shoulder joint, unlike other body joints, has few ligaments holding it in place. Tendons and muscles substitute for the ligaments. This arrangement adds to risks for shoulder injuries.

One common shoulder injury is biceps tendinitis. The biceps is the muscle on the front of the upper arm. Pain from an inflamed biceps tendon is felt in the front of the shoulder. Bringing the hand upward to touch the shoulder intensifies pain. Shoulder bursitis produces pain on the side of the shoulder’s topmost prominence.

Your injury sounds like rotator cuff inflammation. The tendons of four back muscles lie in close proximity to each other when they sweep around the shoulder. They form the rotator cuff. They hold the shoulder in place, and they are easily inflamed. Rotator cuff pain is felt when reaching overhead or when trying to put an arm through a coat sleeve. Its pain worsens at night. Lying on the affected shoulder is impossible.

Anti-inflammatory medicines — naproxen, ibuprofen and their many relatives — relieve pain and lessen inflammation. Four times a day, apply heat from warm compresses or a heating pad for 10 minutes. When sleeping on your back, putting a pillow under the shoulder often relieves pain.

If matters have not cleared up within three weeks, see the family doctor. You might have torn the rotator cuff, and surgery might be necessary.

DEAR DR. DONOHUE: Now that spring is here, I can start running again. Every spring I suffer from blisters on my feet. I would like some advice on how to prevent and treat them. — F.M.

ANSWER: Friction causes blisters. One layer of skin rubs against a lower layer. A cleft forms between the layers and soon fills with fluid. Prevention of friction prevents blisters.

A light coat of petroleum jelly on the soles minimizes friction. It works only for one hour. If you plan to run longer than that, either don’t use it or carry some with you and reapply it.

Sweaty feet promote friction. Wear socks made from acrylic fiber. The fiber wicks moisture away from the feet and keeps them dry.

Have you tried an inexpensive cushioned insole? If not, do so.

Small blisters can be left alone. Don’t puncture them. Protect them with a doughnut-shaped pad, the blister sitting inside the doughnut hole.

For large blisters, first gently wash the foot with antibacterial soap. Drain the fluid from large blisters by puncturing them with a needle that has been sterilized in a flame and then allowed to cool. Keep the roof of the blister in place. It provides protection. A protective pad over the blister shields the blister from more friction.

DEAR DR. DONOHUE: I am pregnant for the first time. The baby is due in about five months. Before pregnancy I took yoga classes and loved them. I would like to continue now. Is it safe? — D.M.

ANSWER: It’s safe for most yoga exercises that emphasize different body positions, breathing and relaxation. It is not safe for any exercises that require extreme positions, like standing on the head or lying on the stomach.

Ligaments are more lax during pregnancy. You’ll find you can stretch further than you ordinarily can. Don’t overdo the stretches.

There are yoga classes specifically for pregnant women.

Only one person can approve of exercises for you — your doctor.

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.