If you're a runner, chances are you'll deal with a bruised toenail or two at some point in your running career. Although bruised toenails are more common in people who run, you don't necessarily have to be a runner to develop toenail bruising. Soccer players are also susceptible due to the trauma of repeatedly kicking the soccer ball. Any way you look at it, bruised toenails are not pretty and they can be painful. They usually turn an unattractive shade of black or dark blue and can be quite disfiguring, especially if you wear open toed shoes or sandals.

What causes the toenails to bruise and turn a dark color? Toenail bruises usually result from repetitive trauma to the feet and toes due to excessive running or wearing shoes that are too tight during physical activity. This usually occurs after buying a new pair of running shoes that haven't been broken in or after running a marathon. Downhill running can also cause toenail bruises since the big toe is forced against the tip of the running shoe which causes excessive trauma. Another cause of bruised toenails are toenails that haven't been trimmed properly before undertaking physical activity. The ugly, black color that results when a toenail is bruised is a consequence of blood collecting underneath the nail plate.

Although unattractive to look at, a black toenail may or may not be painful. The degree of pain that's experienced depends upon whether there is significant fluid build-up behind the affected nail. Fluid pressure can cause irritation and pain in the toe which makes wearing shoes very uncomfortable. In cases where there's significant pain, your doctor can make a small hole in the nail to allow fluid drainage and relieve the excess pressure behind the nail. Complete removal of the black toenail may also be recommended. A new toenail will grow back in four to six months.

If a bruised toenail is painless, no treatment may be necessary. As the bruised skin underneath the nail starts to heal, separation of the toenail from the nail bed may occur causing the toenail to fall off. Although you may not feel comfortable wearing sandals, fresh toenail will replace it in about five months. Avoid pulling the nail off if it starts to separate. It's best to allow the toenail loss to occur naturally.

To prevent future black toenails, select running and exercise shoes that fit properly and keep your toenails well trimmed. Be sure to wear socks and make sure the laces of your running shoes are tight to prevent slippage of the foot in your running shoe. If you develop a black toenail that's unassociated with running or trauma or if you notice severe redness or swelling of a toe, it's important to see your doctor or podiatrist to rule out other foot problems.

A bruised toenail can be a frustrating problem. After running or excessive exercise, make it a habit to inspect your toes for any areas of redness, discoloration, or swelling. Being alert to toenail problems early can help to prevent future foot discomfort and loss of running time.