Blood blister

on palm of right hand

Large blood blister on right foot

A blood blister is a type of blister that forms when subdermal tissues and blood vessels are damaged without piercing the skin. It consists of a pool of lymph, blood and other bodily fluids trapped beneath the skin. If punctured, it suppurates a dark fluid. Sometimes the fluids are cut off from the rest of the body and dry up, leaving behind dead cell material inside the blister with a texture like putty. Some blood blisters can be extremely painful due to bruising where the blister occurred.

Prevention

Common areas that suffer from blood blisters include the hands and feet.

When the cause is abrasion, moleskin can be used to prevent blood blisters from forming. Blood blisters are commonly caused by accidents in which the skin is pinched by a tool, mechanism, or heavy weight without protective gear. The only prevention in these situations is to use tools carefully and wear appropriate protective gear. Blood blisters also may occur with constant rubbing back and forth, or as a result of frostbite.

Treatment

There are several methods of healing blood blisters, including elevation of the wound, application of a cold pack, and application of padded dressings or splints.

See also

• Bleeding
• Blister
• Bruise
• Cherry hemangioma