Friction, Fungus Can Thicken Toenails

Q:  I am wondering why my fingernails are soft and always breaking (especially when doing laundry, household tasks, etc.); whereas my toenails are so hard it takes the podiatrist's sharpest and strongest tools to cut and trim them. Aren't toenails and fingernails basically made of the same stuff?

A:  Fingernails and toenails are made of the same type of tissue, but just as the soles of the feet are much thicker than the palms, toenails are harder and thicker than fingernails because of more constant friction from socks and shoes.

Fingernails are usually exposed to water, soaps and chemicals much more than toenails, which can cause them to dry out and crack or split. Keeping hands and fingernails moisturized, especially during the winter, may help alleviate the problem.

Fungal infection of the toenails (called onychomycosis) can also make them very thick, yellowed and hard. According to the National Onychomycosis Society, nail fungus is a common problem, affecting almost 30 million Americans. The fungus destroys keratin, the protective outer layer of nails, hair and skin. As a result, the keratin goes into over-production, causing an excess that can push the nail away from the nail bed.

Anti-fungal medications taken in pill form are available to treat onychomycosis, but can have quite a few unpleasant side effects. There is also a nail lacquer treatment available that is painted onto the toenails. These remedies work on the new nail that’s growing in, and can take up to a year to be fully effective.

"Dear Doctor" is a compilation of patient questions answered by doctors from the Medical College of Wisconsin.