DEAR DR. DONOHUE: What can be done for blisters, both when you have them and when you don’t but want to prevent them? I get them on my feet. They’re a big nuisance for me, and they keep me from playing my favorite sport – basketball. I’m not going to make it to the pros if you don’t come across with some great information. – B.G.

The advice might not be great, but it’s as good as I have.

Friction causes blisters. The outermost layers of skin slide over the deeper skin layers. Sliding creates friction, which creates heat. Fluid rushes into the space between the two skin layers, and you end up with a blister. No matter where a blister forms, friction is the reason why it pops up.

Regularly coming down with foot blisters strongly suggests you need a change of shoes and socks. Get shoes that pad your feet and are neither too big nor too small for you. If the shoes are too big, your feet slide around in them. If they’re too small, there’s no room for even a little movement, and cramped feet can’t distribute the shock of the feet hitting floor to the entire foot surface. Adequate padding of the soles reduces friction. Moisture is another ingredient that generates blisters. Wear acrylic socks; they wick moisture away from the skin.

If you have a blister, try to keep the roof of the blister intact. Drain the fluid by puncturing the blister with a sterile needle. The collapsed blister roof then serves as a good covering for the raw skin beneath it.

If there’s a particular spot that is the constant site of blisters, pad that area before you play.

DEAR DR. DONOHUE: A year ago, I had a stroke that left me with a weak leg. I can’t jog or walk too well, but I want to start exercising. Do you think a stationary bike would be a good investment for me? How many miles a day should I do on the bike? – J.K.

Don’t buy a bike until you’ve tried it out. Make sure you can pedal it, and clear the exercise with your doctor.

A stationary bike, all things considered, is an excellent way to stay in shape and to keep your heart healthy. Don’t fret about the number of miles you have to rack up daily. Pay attention to the time you spend on the bike and the pace at which you pedal it.

Begin your program modestly, pedaling at a leisurely pace and spending only three to five minutes doing so. Slowly increase the amount of time and pedaling speed. By this time next year, you should be spending 30 minutes on the bike every day. You can break those 30 minutes into three 10-minute sessions. In a year’s time, your pedaling speed should be around 80 pedal strokes a minute. One pedal stroke is a complete revolution of one foot – e.g., right foot in the down position, then in the up position and then back down again.

DEAR DR. DONOHUE: I have a couple of stretching questions. How far should the stretch be? As far as you can possibly go? How long should you hold a stretch? I’ve been told from a few seconds to a whole minute. – T.R.

Before you stretch, warm up. Warming up is doing something like jogging in place. Warm muscles and tendons can stretch farther than cold ones, and warm ones are less likely to be injured.

Stretch to the point where you’re a bit uncomfortable but not in pain.

Hold the stretch from 10 to 30 seconds. Start out with 10 seconds and work up to the 30-second limit.

Don’t hold a stretch if it is painful.

DEAR DR. DONOHUE: How much does exercise really add to your life? I am not an exerciser and don’t intend to become one. – S.K.

I don’t know if this is reliable, but some claim it adds an extra year or two to your life. Length of life is not what counts. Quality of life is. Exercisers are more likely to maintain their independence right to their last moments on Earth.

DEAR DR. DONOHUE: I am 63, married and have sex once a week. Three years ago I started having urinary tract infections more frequently than I had ever had them in the past. Antibiotics help, but I hate taking medicine. The infections occur within 24 hours of having sex. This makes me not want to have sex. Can you help? – S.M.

Women are prone to having bladder infections because their urethra – the tube that empties the bladder to the outside world – is shorter than men’s, and its opening is in an area that is teeming with bacteria. Intercourse massages bacteria into the urethra, and that’s why it can lead to infections.

If you take a single dose of an antibiotic after relations, you can put an end to intercourse-caused bladder infections. Or urinating right after relations flushes bacteria from the urethra and prevents bladder infection.

If you’re dead set against medicines, try drinking 8 ounces of cranberry juice every day. You must make it a habit. Taking it only when you have an infection doesn’t give it enough time to work well.

The booklet on urinary tract infections discusses both kidney and bladder infections in detail. Readers can obtain a copy by writing: Dr. Donohue – No. 1204, Box 536475, Orlando, FL 32853-6475. Enclose a check or money order (no cash) for $4.75 U.S./$6.75 Can. with the recipient’s printed name and address. Please allow four weeks for delivery.

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

Only subscribers are eligible to post comments. Please subscribe or to participate in the conversation. Here’s why.

Use the form below to reset your password. When you've submitted your account email, we will send an email with a reset code.