Most blisters heal on their own within a week or two if you protect them and resist the urge to pop them. The intact skin over a blister acts as a natural barrier against bacteria, so your main job is to keep that barrier in place, reduce friction on the area, and watch for signs of infection. What you do in the first day or two makes a real difference in how quickly and cleanly a blister heals.
Leave It Intact When You Can
If a blister isn’t causing significant pain or interfering with walking or gripping, the best thing you can do is leave it alone. The fluid inside (called serum) cushions the damaged skin underneath while new skin forms. That thin roof of skin is a surprisingly effective sterile dressing all by itself, and breaking it open invites bacteria in.
Cover the blister with a bandage to protect it from further rubbing. If it’s in a high-friction spot like your heel or the ball of your foot, moleskin works better than a standard adhesive bandage. Cut a piece of moleskin about an inch larger than the blister on all sides, then cut a hole in the center that matches the blister’s size. This creates a donut shape that surrounds the blister without pressing on it. Cover the whole thing with gauze.
Hydrocolloid bandages are another strong option. These contain a gel-forming material that absorbs fluid and creates a moist healing environment while sealing out dirt and germs. They’re soft enough that they won’t stick to or pull on the blister, and they stay put better than regular bandages during activity. If you apply any ointment first, let the skin dry completely before placing a hydrocolloid bandage on top, or it won’t adhere properly.
If It Pops on Its Own
Blisters break. It happens, especially on feet. When it does, leave the loose flap of skin in place. Gently smooth it back down over the raw skin underneath. That flap, even though it’s dead, still provides a layer of protection while the new skin forms. Don’t peel it off unless you see pus beneath it or the area looks infected.
If the skin flap is torn or dirty, wash the area gently with mild soap and water, then try to lay the flap back in place as best you can. Apply a thin layer of petroleum jelly to keep the wound moist. The American Academy of Dermatology notes that plain petroleum jelly works just as well as antibiotic ointment for wounds that aren’t infected, and antibiotic creams can actually irritate the skin and cause a painful, itchy rash called contact dermatitis. Choose petroleum jelly from a tube rather than a jar to keep it clean. Cover with a bandage and change it daily.
Blood Blisters Need Extra Caution
Blood blisters look like regular friction blisters but are filled with blood instead of clear fluid, giving them a red, purple, or dark appearance. They form when small blood vessels beneath the skin get pinched or crushed, usually from a sudden impact rather than gradual rubbing.
Never pop a blood blister. The deeper tissue damage involved makes infection a greater concern than with ordinary friction blisters. Wash the area gently with mild soap and water, apply an antibacterial ointment, and cover it with a bandage. Change the bandage at least once a day and keep the area clean and dry. If a blood blister is painful, apply an ice pack wrapped in cloth for short intervals. Over-the-counter pain relievers like ibuprofen or acetaminophen can also help.
How to Spot an Infection
Check your blister daily. An infected blister feels hot to the touch and fills with green or yellow pus instead of the normal clear or slightly yellowish fluid. The skin around it typically turns red, though this can be harder to notice on darker skin tones. You might also notice increasing pain, swelling that spreads beyond the blister’s edges, or red streaks radiating outward. Any of these signs mean the blister needs medical attention rather than home care.
Preventing Blisters in the First Place
Friction and moisture are the two ingredients behind nearly every blister. Reduce either one and you dramatically lower your risk.
Socks and Shoes
Cotton socks trap moisture against the skin, which softens it and makes it more vulnerable to shearing. Synthetic moisture-wicking socks made from acrylic, nylon, or polyester pull sweat away from the foot and significantly reduce blister formation. Make sure your shoes fit properly. A shoe that’s too tight creates constant pressure, while one that’s too loose allows your foot to slide and rub.
Tape and Skin Coverings
If you know where you tend to blister, preventive taping is one of the most effective strategies. Paper surgical tape applied directly to the skin before activity has been shown to reduce blister occurrence. Moleskin and zinc oxide tape also work well. These create a barrier so the friction happens between your sock and the tape rather than between your sock and your skin.
Reducing Moisture
Foot antiperspirants containing 20% aluminum chloride hexahydrate, the same active ingredient in many over-the-counter antiperspirants, significantly reduce blister formation by keeping skin drier. Friction-reducing powders can also lower skin hydration near the surface. Apply either one before putting on socks.
Lubricants and Insoles
Anti-chafe balms and sticks are popular among runners and hikers, though the evidence for them is mostly anecdotal rather than scientifically validated. They work by reducing the friction coefficient between skin surfaces or between skin and fabric. Neoprene insoles take a different approach, absorbing the shearing forces that would otherwise transfer to the skin of your foot. Both are worth trying if you blister frequently, especially during long hikes or runs.