Toenail fungus or onychomycosis is the most common cause of toenail abnormalities and 6-8% of the adult population suffers with it. Toenail fungus is caused by a number of things and can be easily prevented with good hygiene. The most common causes of this condition are the Candida mold and dermatophyte fungi. Candida is the more common cause of toenail fungus in warm, tropical climates and also effects people who spend long hours with their nails submerged in water but should not be confused with Trenchfoot caused by similar conditions but which effects the skin and flesh as well. Other risk factors include genetic predisposition towards acquiring toenail fungi, old age, and prior trauma to toenails, communal showers, immuno-suppressants and too tight non-aerated footwear. To prevent toenail fungus always wear comfortable, well-fitting shoes, allow shoes to dry thoroughly before wearing again, wash feet daily and thoroughly, wear flip-flops in communal showers and trim your toenails. The best treatment for toenail fungus is to avoid contracting it in the first place.