Blisters are fluid-filled bumps that look like bubbles on the skin. They usually form when someone’s skin repeatedly rubs against something or is exposed to heat. When the inner layer of the skin is damaged, leaks fluid that collects under the top layer of the skin, forming a blister.
Blisters
Dr Lynn Thomas, OStJ, BSc, MB.BS, MA, FRCPClinically reviewed: 28/04/2025
Blisters are common on the feet and can be caused by ill-fitting shoes, but can appear anywhere on the skin. Learn what to look for and how to perform first aid.
What are blisters?
What to do
- 1
If someone has a blister, don’t burst it as this can increase the risk of infection. Wash the skin around the blister with clean water and gently pat the skin dry with a sterile gauze pad or a clean, non-fluffy cloth.
If you cannot wash the area, try to keep it as clean as possible.
- 2
The blister was caused by something rubbing against the skin, cover it with a plaster but make sure the pad on the plaster is larger than the blister area. Ideally use a special blister plaster, as these have a cushioned pad that gives extra protection.
