Blisters are small, swollen pockets of bodily fluid in the upper layers of the skin. They can be caused by repeated friction, burning, freezing, chemical exposure, injury, or infection. Most blisters on the feet are friction blisters.

Preventing Blisters

Friction blisters on the feet are usually caused by walking long distances or by improperly fitting shoes (or both). Here’s a few simple tips to avoid them:

  • Make sure your shoes fit properly. A shoe that is too tight or too loose will place pressure or friction in unexpected places, which can often result in blisters.
  • Avoid overexertion. If you’ve been walking, running, or playing a sport for a long period of time, you might want to give your feet a rest. If you notice any pain or discomfort, stop right away.
  • Keep your feet dry. Friction blisters tend to form more easily on moist skin than on dry skin. Make sure your shoes and socks allow for adequate ventilation to keep sweat from building up. Foot powder may also help eliminate moisture.
  • Protect the skin. If you know a part of your foot tends to develop blisters during a certain activity, try taping or padding the area before hand to reduce the amount of friction upon the skin.

Treating Blisters

If you do develop a friction blister on your foot, it is best to let it heal on its own (which means don’t pop it). Apply a loose bandage over the area to prevent additional friction on the area while the blister heals. If the blister is in an area that bears weight, try padding the area with a moleskin donut (a circle of moleskin with a hole cut out to leave the blister uncovered).

On occasion, it might be necessary to pop the blister if it is particularly large or painful due to pressure. In such circumstances, sterilize a small, clean needle with rubbing alcohol. With the needle, carefully poke a small hole in the side of the blister near the foot. Gently press the blister to express the fluid. Note that if you have a condition such as diabetes that leaves you at risk of infections, you should not drain the blister on your own; check with your podiatrist.

If you drain the blister or if the blister bursts on its own, clean and disinfect the area thoroughly to prevent infection. Cover the area with a bandage to prevent any further pressure and to keep it clean. Petroleum jelly can help to reduce friction as well. Unless it has become torn and dirty, do not remove the loose skin (the “roof” of the blister), as it will still protect the sensitive lower layers underneath.

Keep an eye on the blister for signs of infection, such as increased pain, swelling, redness, warmth, red streaks in the skin, or drainage of pus rather than clear liquid. If the blister becomes infected, check in with your podiatrist to ensure the matter is resolved properly.