Subungual hematoma
Overview
Blood
Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....
(hematoma
Hematoma
A hematoma, or haematoma, is a localized collection of blood outside the blood vessels, usually in liquid form within the tissue. This distinguishes it from an ecchymosis, which is the spread of blood under the skin in a thin layer, commonly called a bruise...
) underneath a toenail or fingernail
Nail (anatomy)
A nail is a horn-like envelope covering the dorsal aspect of the terminal phalanges of fingers and toes in humans, most non-human primates, and a few other mammals. Nails are similar to claws, which are found on numerous other animals....
(black toenail). It can be extremely painful for an injury of its size although otherwise it is not a serious medical condition. Is is sometimes known as runner's toe or tennis toe.
Runner's toe is a common condition seen in runners
Running
Running is a means of terrestrial locomotion allowing humans and other animals to move rapidly on foot. It is simply defined in athletics terms as a gait in which at regular points during the running cycle both feet are off the ground...
caused by downward pressure or horizontal separation of nail plate
Nail plate
The nail plate is the hard and translucent portion of the nail, composed of keratin.- See also :* Runner's toe, repetitive injury seen in runners...
from the nail bed
Matrix (nail)
The formative layer of cells at the base of the fingernail or toenail. This tissue consists of rapidly dividing skin cells that soon fill with the protein keratin...
.