Whether a discolored, black toe nail requires medical treatment depends on the severity of the injury, according to Foot Vitals. If the injury is not painful, it is best to leave it alone. If pain is severe, it is best to see a podiatrist immediately to determine the required treatment.
The black discoloration of the toenail is caused by bruised or broken blood vessels under the toenail, typically caused by trauma, says Foot Vitals. If injury to the toe is mild, the injury heals on its own without any need for treatment. The toenail eventually grows out, falls off and a new nail grows back in its place.
With a more severe injury, there is significant pressure under the toenail caused by a subungual hematoma, which is described by Foot Vitals as the pooling of blood under the nail. The podiatrist uses one of three methods to drain the subungual hematoma: completely removing the nail, draining the blood using a large-gauge needle, or using a device to burn a hole in the nail and draining the blood. Following professional treatment, a doctor may suggest foot baths of Epsom salt and lukewarm water followed by an antibiotic ointment twice a day. Black toenails typically take several months for the toenail to grow back and heal completely.