A to Z: Subungual Hematoma

A subungual hematoma (sub-UNG-gwal HEE-muh-toe-muh) is blood trapped under a fingernail or toenail, often due to an injury such as a stubbed toe or a finger slammed in a door.

More to Know

A subungual hematoma is a common and painful injury. The injured area under the nail bleeds and, as a result, turns a blue-black color. Someone with a subungual hematoma might feel a throbbing pain under the nail, which often becomes worse as the blood spreads. The pain usually goes away after the blood is drained.

Keep in Mind

Treating a subungual hematoma involves examining the nail to see if it's still intact and if the finger or toe had any other injuries. If the nail itself was severely injured, it may be removed. Otherwise, a procedure called trephination will be performed. This involves putting a tiny hole in the nail and draining the blood trapped beneath it. This relieves the pressure under the nail and helps pain improve quickly.

The finger or toe will be wrapped in a bandage, and a splint might be used to protect the area if there are other injuries to the finger or toe.

All A to Z dictionary entries are regularly reviewed by KidsHealth medical experts.