Why is my toenail falling off?

Dear Reader,

The loss of a toenail, also called onychoptosis (which literally means "falling nail" in Greek), can be largely blamed on two major culprits — fungus and injury.

Fungus: Several different types of microscopic fungi can cause onychoptosis by feeding on keratin, the tough protein that makes up toenails. Onychoptosis caused by fungus isn't that rare a problem — three to five percent of Americans are affected, as are up to 18 percent of people worldwide.

Toenail fungus can cause toenails to do the following:

• Turn yellow, brown, or white
• Become thick and overgrown
• Crumble and fall off

Nails that fall off because of fungal infection will grow back, but the new nail will probably become infected, similar to the old one. Since the condition rarely goes away on its own, it's smart to talk with a health care provider about an accurate diagnosis and then possible treatments. After examining your foot, the provider may remove a large amount of the infected nail (if there's any of it left). Depending on the extent of the infection, s/he may also give you a prescription anti-fungal toenail polish, such as Loceryl or Loprox, or oral anti-fungals, such as Sporanox and Lamisil. If a toenail resists treatment, it can also be removed surgically.

The fungi that cause onychoptosis thrive in dark, moist environments, so wearing tight shoes, socks, and stockings, as well as thick nail polish, can increase your risk of developing the condition. The fungi are also easily transferred from foot to foot and from person to person, hence why locker rooms are notorious for transmitting such things as toenail fungus and athlete's foot. An inexpensive pair of sandals or shower shoes can help you avoid picking anything up the next time you hit the showers.

Injury: Might you be an athlete? When you kick a soccer ball, pivot for a fade-away jumper, or stop short at the net for a volley, your toes can get jammed against your shoes, sometimes causing a trauma that can result in the loss of a nail. If a toe gets smacked hard or repeatedly, the result can be a subungual hematoma — painful bleeding under the toenail that can, in more serious cases, cause the nail to fall off. If a subungual hematoma appears to be expanding quickly, it's a good idea to have a health care provider or trainer help you drain the blood from under the nail, a treatment that, when done quickly and correctly, can help keep the nail from falling off. If the blood appears to have spread to more than 25 percent of the nail, it's wise to have a health care provider examine the toe for bone fractures.

Whatever the cause of your nail loss, a replacement will most likely grow back within several months. To prevent further foot problems and maintain happy and healthy toenails, keep these suggestions in mind:

• Wear fresh socks made of natural fibers (e.g., cotton) or synthetic materials that wick moisture away from the skin, allowing your feet to breathe.
• Buy well-fitted shoes that give your toes plenty of room. For example, wear shoes that have a wide toe box, rather than pointed toes.
• Keep your toenails trimmed across in a straight line.

That will likely help you nail down the problem.