Blackening of the toenail near its base. It may be very painful and accompanied by swelling. Black nail is commonly caused by the patient's shoe being too short or too wide so that the foot slides forwards and jams against the end of the shoe, especially on dry, artificial turf. Black nail may also be caused by a direct blow to the toe. The nail later dies and grows out, with the black area growing away from the nail bed and eventually dropping off. Black nail can be prevented by wearing well-fitted shoes. It can be treated by inserting a heated, sterilized pin (or the end of a paper clip) through the nail to create a hole that releases the blood. See also turf-toe syndrome.
Subjects: Sports and Exercise Medicine.