Toenail fungus infections occur when microorganisms called fungi to begin to grow and spread under the toenail. A fungal infection requires medication. Toenails are susceptible to fungal infections because the environment inside your shoes is perfect for fungal growth. Fungus thrives more in a dark, warm, and moist environment.
You are more at risk of toenail fungal infections when you are older, when you wear inappropriate footwear such as unclean socks and tight shoes, when you walk barefoot in public places that are damp like public pools, and when you have chronic health conditions like diabetes.