What Is It?

A friction blister is a soft pocket of raised skin filled with clear fluid caused by irritation from continuous rubbing or pressure. Friction blisters most commonly occur on the feet, where tight or poor-fitting shoes can rub and irritate delicate toes and heels for long periods of time. This type of irritation causes minor damage to the skin and the tissue just beneath the skin, leading to the accumulation of fluid just beneath the outermost layer of skin. If the irritation is enough to damage small blood vessels, the blister also may contain blood and is then called a blood blister.

A friction blister is a small pocket of puffy, raised skin containing clear fluid. It is usually painful when touched. A blister can appear anywhere that continuous friction or pressure has been applied, especially on the feet.

The presence of a blister in a place susceptible to pressure is all that is necessary for diagnosis. In short, if it looks like a blister and feels like a blister, it likely is a blister.

Friction blisters typically drain on their own within days. A new layer of skin forms beneath the blister, and eventually the blistered skin peels away.

If continued pressure or friction is applied to the same area, the blister may last two weeks or longer. Because continued friction may rub away the delicate top skin layer, the blister may break open, ooze fluid and run the risk of infection or a deeper wound. If the irritation is mild, it may heal despite continued irritation, and eventually a callus will form.

The best way to prevent friction blisters is to wear shoes that fit your feet well, so that the shoe is not tight anywhere and does not slide up and down your heel when you walk. Wear socks with shoes to protect your feet and prevent irritation, and try to keep your feet dry. If another activity is causing blisters — for example, if learning to play golf is causing blisters on your hands — ask an instructor to point out other ways to perform the same activity in a nonirritating way, and take advantage of protective devices, such as gloves.

Because blisters typically get better on their own in just a few days, generally no special treatment is required other than to keep the blisters clean and dry. Because the skin provides a natural protection against infection, a blister should be left intact if possible. Do not try to drain the blister or pierce or cut away the overlying skin. Try to avoid further irritation, or protect the blister with a sterile bandage if continued irritation is unavoidable. If the blister breaks on its own, wash the area with soap and water, gently pat dry, use an antibacterial ointment and cover it with a bandage.

People with diabetes and people who cannot reach blisters readily (because of a physical disability or other ailment) may need to have their blisters evaluated by a foot specialist (podiatrist) or other health-care professional. People with diabetes often have nerve or circulation problems that make it more difficult to recognize wounds, and that slow wound healing. In these people, a simple foot blister might go unrecognized and possibly become infected. Caring for feet daily and examining them for sores or blisters are important steps for anyone with diabetes.

Widespread blistering, itchy blisters or blistering in a place that has not been exposed to rubbing or pressure should be evaluated by a physician. These are signs of an illness, not friction blisters.

For typical blisters, medical care is needed only if an infection develops. This is more likely to occur if the skin over the blister has been pierced, broken or popped. These types of blisters need to be watched for a few days to make sure they heal properly. If you think you have an infection, see significant redness, notice drainage that is not clear fluid or develop a fever, see your doctor immediately. Also, if the blister is so large or painful that walking or other activities become difficult, seek professional help.

People with diabetes who experience blisters frequently or have blisters that don’t seem to heal should see a health-care professional.

Most blisters heal on their own in a few days. If there is continued pressure or friction to the area, it may take two weeks or longer for the blister to go away.

Diseases and Conditions Center

All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.