Causes
There are basically 3 main organisms that are responsible for nail fungus that include the dermatophytes, yeasts, and molds. All of the organisms responsible for nail fungus cause the same symptoms, and it is impossible to differentiate based on clinical appearance. The dermatophytes (Epidermophyton, Microsporum, and Trichophyton species) are the most common causes of onychomycosis then yeasts and molds.
Associated risks for becoming infected with onychomycosis include: Using communal showers at the gym or community pools, walking barefoot outdoors either in grass or at the beach, living in a warmer has also been associated with nail fungal infections since these infectious organisms thrive in warm moist environments, advancing ages, poor health, trauma to the nail or nail bed, pedicures, immunosuppressive conditions such as HIV or from drugs used to suppress the immune system and wearing shoes that don't provide enough airflow to the feet.