Many runners have been surprised to take off their socks after a run to notice that one or more of their toenails is turning black and blue. Many times the bruised toenails can look much worse than they are, but there is actually a simple explanation for this condition.
If a runner does not wear shoes that fit them properly then their feet are able to slide in their shoes. This can occur if running shoes and too big because the foot will slide around in the shoe and bang up against the front edge. This can also occur if shoes are too small because the toes begin to jam up against the front of the shoe. This is why it is so important to get shoes that fit properly in order to prevent the toes front hitting the front of the shoe to hard.
If the nails are turning black and blue from the toes hitting up against the front edge while running don’t be alarmed. The color change is from micro lesions under the nail from where tiny capillaries have broken. If you notice this discoloration the best way to get rid of this is to stop running in the same shoes that caused this condition.
Most of the time the discoloration does not cause much discomfort, however, the nail can become infected if it is not kept clean so make sure you wash around the nail to prevent infection from occurring. Sometimes if there is enough bleeding under the nail pressure can build which will cause discomfort. If the nail starts to become painful, then you will want to go to get evaluated by a podiatrist. The pain either signifies infection or pressure build up from bleeding under the nail, both of which can be easily treated by a podiatrist.
A bruised nail does not automatically mean that you will lose the toenail. If there is substantial bleeding beneath the nail and a podiatrist relieves that pressure quickly, then the nail can reattach to the nail bed. Otherwise, the prolonged trauma from the pressure can cause the nail to detach and a new nail to begin forming and growing. If that occurs, the original, damaged nail will simply fall off when the new nail has progressed. As long as the nail comes off with no pain or bleeding, there should be no concern.
Bruised nails are a common sign of running shoes not fitting properly. If this occurs, get new running shoes. Your best bet is to visit a specialty running store, which has staff trained to properly assess your needs to recommend the right shoe for you and to ensure that shoe fits properly. If you have any pain with the injured toenail, be sure to get in to visit your podiatrist.