The most common symptom of toenail fungus is a progressive deterioration in the color and quality of the toenails, resulting in dark, thick toenails, states the American Podiatric Medical Association. Since the infection is painless in many instances, many sufferers may ignore the condition for years.
Toenail fungus, or onychomycosis, is a fungal infection of the area underneath the nail, explains the American Podiatric Medical Association. The infected toenail usually darkens in color, emits a foul odor and becomes thick enough to cause pain while walking. If left untreated, the infection may spread to other toenails, the skin and fingernails, and it may cause a secondary bacterial or yeast infection in the affected toe. Causes of onychomycosis include excessive perspiration, injury to the nail bed, walking barefoot in damp areas, a history of athlete's foot, and chronic diseases, such as diabetes.
Treatment for toenail fungus includes long-term daily cleansing, oral antifungals and topical medication for mild infections. Temporary or permanent surgical removal of the diseased nail may be necessary for severe cases, adds the American Podiatric Medical Association. A patient should follow the professional advice of his podiatrist to treat the condition effectively and to prevent an infection from coming back. Proper foot hygiene and keeping the feet clean and dry can help prevent onychomycosis.