Fungal nail infection is caused by a fungal condition called Onychomycosis and results in thick or discoloured toenails. If you have an athlete's foot infection this can spread to the toenail and cause a fungal nail infection. Older people and people with certain medical conditions such as diabetes are at an increased risk to fungal nail infections.
The fungi that causes a fungal nail infection is highly contagious and can be picked up in communal locations such as public swimming pools. If you have an athlete’s foot infection this can spread to the toenail and cause fungal nail. If you have a toenail that is already damaged you can also be more susceptible.
Fungi thrive in warm, moist conditions. The wet floor of a public changing room is a common breeding ground for fungi, as are hot, sweaty shoes. Anything that comes into direct contact with an infected nail can become a carrier of the fungus, spreading it to other nails on the feet and hands, or to other people.