The risk of getting a fungal nail infection depends on your susceptibility to fungal infection.

Risk factors you cannot change

Risk factors you cannot change include:

• Susceptibility to fungal infection (which is not yet well understood) or a history of fungal infections.
• Impaired immune system (caused by certain diseases, such as AIDS, diabetes, or cancer, or certain immunosuppressive drugs, such as corticosteroids).
• Poor blood circulation (caused by disease or increasing age).
• Age. People older than 60 are more likely to have a fungal nail infection.⁵
• Being male.

Risk factors you can change

Risk factors you can change include:

• Wearing tight shoes.
• Wearing shoes that make your feet warm and sweaty.
• Wearing the same pair of moist shoes for 2 days in a row (and not letting your shoes dry out).
• Sharing personal items such as shoes, socks, nail clippers, or nail files with other people.
• Living in a hot, humid climate.
• Using public or shared showers or locker rooms without shower sandals or shower shoes.
• Injuring the nail (as in the case of frequent nail trimming).
• Having athlete's foot. For more information see the topic Athlete's Foot.
• Having a job in which your hands or feet are often wet (such as dishwashers or lifeguards).
• Smoking.
• Wearing artificial nails. An infection can develop in the gap between the artificial nail and the real nail, especially if a loose nail is glued back on without first being cleaned with rubbing alcohol. Nail manicure and certain nail products can damage the nail or cuticle, making the nail more susceptible to infection.