Black or darkened toenails can be indicative of many different things.  The discoloration can be due to bleeding under the nail, which can be caused by direct trauma or by banging of the toenails in the shoe. Runners and tennis players often suffer from this problem. The medical term for this is called subungual hematoma. It may be commonly referred to as “Runners Toe” or “Tennis Toe”.  “Runners Toe” and “Tennis Toe” make the toenail more prone to fungal infections. Our skin and nails are our body’s defense to the environment. When the nails are continually damaged, they become prone to infection, especially fungal infections.

If a subungual hematoma is caused by direct trauma (i.e. dropping something on the toe or kicking something), it is always a good idea to see a Foot and Ankle Specialist to get an X-ray of the toe to make sure there is no fracture involved. If the subungual hematoma involves more than 50% of the nail, the toenail is typically removed to ensure there is no underlying nail bed laceration, which requires repair.

Another reason nails can become dark or discolored is a fungal infection of the nail. Some molds leave a black debris under the toenail.

A black or brown pigmentation of the nail plate may be a normal presentation as well. It can, however, be the sign of something much more serious. It may be a sign of subugual melanoma or cancer.

If you have a darkened or discolored toenail, it is always best to have it looked at by a Foot and Ankle Specialist so that proper treatment can be initiated, if necessary.