A toenail that becomes infected by a fungi is often referred to as a fungal toenail.  Signs of a fungal toenail are as follows: thick, brittle, discolored, crumbly, rough/jagged edges, distorted shape and/or separated from the nail bed.  Anyone can get fungal toenail infections, but they are most commonly found in those individuals older than 60 years in age.  They are especially common in those individuals that have diabetes or circulation problems and are found more often in men than in women.  Fungi grow in warm, wet places so infections often occur if an individual walks barefoot in locker rooms or sides of swimming pools or if they wear tight shoes that don't allow airflow to the feet.  Fungal toenails are commonly treated with either oral medication or topical creams.