Although most people have healthy, attractive nails, there are various fingernail disorders that can cause considerable distress. Dermatologists (skin specialists) are familiar with these disorders and can help with a diagnosis. The most common nail disorder, however, is probably fungal infection of the nail, or onychomycosis.

Onychomycosis can be broken down into different categories of toe- and fingernail diseases: those that are caused by dermatophytes, those that are caused by saprophytes, and those that are really yeast infections. Dermatophytes are fungi that actually prefer to grow on the nails, skin, and hair. Some of them are specifically adapted to humans, while others commonly infect animals as well. They cause skin infection, such as athlete's foot, and ringworm, as well as toe- and fingernail disorders.

The saprophytes are more accidental causes of fingernail disorders. Present in the environment, they generally live in damp decaying organic material and infect nails only when the opportunity arises. Although some of them are known to cause tissue infection from time to time, as well as fingernail diseases, they do not generally infect the skin. Because these fungi are not dermatophytes, drugs and remedies for onychomycosis may not be tested against them.

Finally, there are the yeasts, causes of toenail and fingernail diseases, as well as vaginal yeast infections, oral thrush, eye infections, and various other conditions. Chief among the yeasts infecting people is Candida albicans, although other species can also do it, particularly in a susceptible individual. Incidentally, we can also thank these organisms for bread and beer, so tissue infections and fingernail disorders are not their only claim to fame. Like the saprophytes described above, these causes of nail infection may require a different treatment approach.

Before choosing any type of treatment for fingernail disorders, sufferers are wise to see a professional