It can be an alarming sight to take off your running shoes and socks only to discover a discolored, black toenail. This condition is often called “runner’s toe,” but it can occur in others outside of the running community as well. It happens due to repetitive trauma to the toe. The discoloration is from blood pooling under the nail. It may look unsightly and can also cause toe pain.
You can stop your toenail from turning black by keeping nails trimmed (straight across and not too short) and wearing properly fitting shoes. Choose shoes that have a wide toe box so your toes aren’t squished, and that are long enough so that the tips of your toes do not jam against the end of the shoe. Avoid socks that are too tight or thick. If your toenail is painful, we may need to drain the fluid under the nail to relieve the pressure.