What Causes Blisters?
Blisters typically develop due to friction on the skin. This can occur from the rubbing of clothing or sports equipment on the surface layer of the skin. Over time, continued friction can cause the top layer of skin to separate from the second layer of skin. (See an image of the skin layers).
One warning sign that a blister is about to develop is redness and warmth on the skin called a "hot spot." Next, fluid fills the space between the top two layers of skin to provide protection from continued rubbing. When this happens you will see a blister that looks like a little bubble on the skin.
Most people get blisters on the heels, soles of the feet, and palms of the hands because they rub against shoes, socks or sports equipment. This type of friction, especially in moist, warm conditions, is perfect for blister development.
How To Prevent BlistersTo prevent blisters you have to minimize friction on the skin. You can do this by wearing appropriate footwear that fits. Some moisture-wicking socks made from synthetic blends can help reduce friction and moisture on the skin of the feet. Some runners commonly tape their blister-prone toes or heels prior to a run to prevent blisters. While band aids and other tape can be used, many athletes (myself included) often use a small strip of duct tape on these trouble spots. Duct tape stays in place for long runs and the shiny back is slick enough to slide on socks and other skin. One other option is to apply petroleum jelly or talcum power before exercise to reduce friction. I've used this as well, and while it works for shorter runs, it's rather messy and wears away on long runs.
If you have any "hot spots" during activity, it's important to apply something right away to prevent the blister from developing. Try to keep your feet dry or change socks if possible. If you can't stop activity or change shoes, socks, gloves or other gear, your best option is to apply one of these blister products to the sensitive area. A simple, quick and effective treatment is to apply a generous amount of petroleum jelly to the area to reduce friction. You will probably need to reapply often.
How to Treat BlistersIf you do get a blister, the goal is to keep the blister from getting bigger and avoiding infection. Signs of infection include pus draining from the blister, very red or warm skin around the blister, and red streaks leading away from the blister).
Small unbroken blisters that don't cause discomfort can be left alone to heal, because the best protection against infection is a blister's own skin. However, large, painful blisters can be drained as long as you keep the top layer of skin intact and covering the blister.
To safely drain a blister, first clean the blister and the surrounding area with rubbing alcohol or antibiotic soap and water. Next, sterilize a needle over a flame until the tip glows red and allow it to cool. Finally, puncture a very small hole at the edge of the blister and drain the fluid by applying gentle pressure. Once drained, place antibiotic ointment on the blister and cover with a bandage and let it heal naturally.
Blisters: First aid. Mayo Foundation for Medical Education and Research. Jan. 11, 2008