Blisters are fluid-filled bubbles that form on the skin of the foot or other parts of the body due to friction or a burn. On the foot, they commonly occur on the heel and toes, areas subjected to friction and rubbing against footwear. Most blisters are filled with clear fluid and do not usually require medical attention; however, larger, more serious, painful blisters may require a visit to the doctor, as they can be filled with pus or blood.

A blister provides a protective barrier so that new skin can form in a clean, sterile environment unexposed to dirt and germs while the skin heals. Since blisters are body’s natural response to protecting the skin, most blisters should not be and do not need to be punctured to release the fluid. To prevent pain and infection, blisters can be covered loosely with an adhesive bandage or special, donut-shaped pad.

If a blister pops or opens, wash it with soap and water only; other solutions could burn and irritate the new skin forming underneath. The protective skin of the blister should never be torn off, even if the blister breaks, as doing so could lead to infection. Apply an antibiotic ointment and adhesive bandage to keep the new skin clean and sterile. If white or yellow fluid oozes from the blister, it is a sign of an infection that needs to be treated by a doctor.

Prevent blisters by wearing properly-fitting socks and footwear. Make sure socks have heels and do not bunch up on the foot. If a shoe causes friction or rubbing in a particular spot, cover the area with an adhesive bandage or petroleum jelly before a blister forms. Break in new shoes slowly over time.