Fungal nail is a type of infection that causes the nail to become thickened and discoloured. Medically it is known as onychomycosis. It more commonly affects the toenails and can cause pain and discomfort if left untreated. An infected nail may appear white, yellow, black or green.
Fungal nail infections are caused by a type of fungi known as dermatophyte. This is the same type of fungi that causes athlete's foot and the condition can spread from the skin to the nail. The yeast candida, which causes thrush, can also lead to fungal nail infections. Health conditions such as diabetes and psoriasis, can be contributing factors as can heat and humidity, so wearing shoes that cause your feet to sweat can increase your likelihood of developing a fungal nail infection. If you have a fungal infection on your toenails and you touch it, it can spread to your fingernails.
Fungal nail most commonly affects the toenails but can form on the fingernails.
Anyone can develop a fungal nail infection however it is more common in older people. Athletes may also be more susceptible.