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Phone: 630-834-3668
Prairie Path Foot & Ankle Clinic

Q
What causes a toenail to turn black?

A

The most common culprit of a black toenail is blood that has dried underneath the nail.  Damage to the ends of the toes and pressure from shoes (a lot of times seen in runners) causes a subungual hematoma. This is a bruising underneath the nail and may start out red/brown but turns black as the blood dries.

- Adrienne B