The best thing you can do for a foot blister is leave it intact. That raised bubble of fluid sits beneath a layer of skin that acts as a natural sterile bandage, protecting the raw tissue underneath from bacteria. Most foot blisters heal on their own within a week or two if you keep them clean, covered, and free from further friction.
Clean It and Cover It
Start by washing your hands and the blistered area with soap and warm water. Pat the skin dry gently rather than rubbing. Then cover the blister with an adhesive bandage or, better yet, a hydrocolloid bandage (the thicker, cushioned type sold specifically for blisters). Hydrocolloid dressings absorb fluid and create a moist environment over the wound that speeds up healing while sealing out bacteria and debris. They’re designed to stay on for several days at a time, which means fewer bandage changes and less disruption to the healing skin underneath.
If the blister is on the bottom of your foot or another pressure point, a standard flat bandage won’t do much. Cut a piece of moleskin into a donut shape, with a hole slightly larger than the blister, and stick it around the area. This lifts pressure off the blister itself while cushioning the surrounding skin. You can place a regular bandage over the top.
When to Drain a Blister
Sometimes a blister is too large or too painful to leave alone, especially if it’s in a spot where walking constantly presses on it. In that case, you can drain the fluid yourself without removing the overlying skin. Wash your hands and the blister thoroughly with soap and water. Sterilize a needle with rubbing alcohol, then make a small puncture near the edge of the blister. Let the fluid drain naturally and press gently with clean gauze if needed.
Leave the loose skin in place. It still serves as a protective layer over the raw tissue. Apply an antiseptic ointment, then cover with a bandage or hydrocolloid dressing. If the blister refills over the next day or two, you can drain it again the same way.
If the Skin Has Already Torn
A blister that has popped on its own needs a bit more attention. Wash the area with soap and water, and gently smooth the remaining flap of skin over the raw base if possible. If the flap is dirty or ragged, you can carefully trim it with clean scissors, but keeping some of that skin layer intact is better than exposing the wound completely. Apply antiseptic ointment, cover it with a bandage, and change the dressing daily or whenever it gets wet or dirty.
Signs of Infection
Most blisters heal without complications, but an open blister on a foot is vulnerable. Watch for increasing warmth around the blister, swelling that spreads beyond the immediate area, a foul smell, pus that looks cloudy or greenish, or pain that gets worse instead of better over the first couple of days. Bleeding when you lightly touch the area, or skin that seems to be peeling away from the wound edges, can also signal a problem.
A red streak extending away from the blister and moving up your leg is a sign of cellulitis, a serious skin infection that needs emergency medical care.
Preventing the Next Blister
Foot blisters are caused by friction, and friction gets worse when skin is damp. Cotton socks are the biggest culprit because they absorb sweat and hold it against your skin. Switching to synthetic blend socks or merino wool makes a noticeable difference. These materials wick moisture away from the surface of your foot, keeping friction lower.
Shoes that are too tight or too loose both cause problems. A tight shoe compresses the skin in one spot, while a loose shoe lets your foot slide back and forth with every step. If you’re breaking in new shoes, apply moleskin or blister-specific tape to your known hot spots (the back of the heel, the ball of the foot, the sides of your toes) before you head out. For long hikes or runs, some people apply a thin layer of petroleum jelly to friction-prone areas as a lubricant.
Blisters and Diabetes
If you have diabetes, a foot blister is not a minor nuisance. Nerve damage from diabetes can reduce sensation in your feet, meaning you might not feel a blister forming or notice when one becomes infected. The CDC recommends that people with diabetes check their feet daily for blisters, cuts, redness, and swelling, using a mirror to see the soles if needed. A blister that doesn’t heal properly can develop into a foot ulcer, and infected ulcers that resist treatment sometimes lead to amputation.
If you have diabetes and notice a blister on your foot, don’t try to drain or manage it yourself. Have it evaluated by your doctor or a podiatrist promptly rather than waiting for a scheduled appointment.