The medical term for toenail fungus is "onychomycosis," pronounced on * EE * ko * my * ko * sis. Despite the commonly used term "fungal toenails", onychomycosis describes both fungus and yeast infections in the nail. The prevalence in America is about 2-3%, but some have reported it as high as 13%. Even at a low estimate of 2%, this accounts for 6 million Americans with toenail fungus. Toenail fungus affects men twice as often as it affects women.

The prevalence among elderly individuals and diabetics is 25%. In the 1800s, fungal toenails were very rare. The increased prevalence is linked to the increased exposure to fungus through the use of showering facilities in gyms, the use of hot tubs, saunas and public pool areas. There is an increase in occlusive footwear, an increase in sporting activities, an increase in diabetes and increase in age of the general population.

The risk factors for developing toenail fungus are increasing age, male gender, nail trauma, sweaty feet, poor circulation, poor hygeine, foot fungus and a compromised immune system.

Athlete's tend to have a higher rate of fungus infection than non-athletes. The moisture in the shoe combined with repeated nail trauma increases the chance of infection. Hikers, runners, backpackers, soccer, basketball and tennis players, athletes wearing loose fitting shoes that allow jamming of the nails against the shoe and any individual wearing shoes that toe tight are at risk for developing toenail fungus.

There are a number of treatments for onychomycosis. The most aggressive and effective way to treat the fungus is with oral anti-fungal medications. The most common oral anti-fungal medications are Itraconazole (Sporonox