Fungal nail infections commonly affect the feet and cause nails to become thick, discolored and brittle enough to crack and break, states the Centers for Disease Control and Prevention. The webs of the toes and soles of the feet may be affected by a common skin infection known as athlete's foot, notes MedicineNet.
A fungal nail infection, or onychomycosis, can lead to yellow, brown or white discoloration of toenails, according to the Centers for Disease Control and Prevention. Yeasts and molds cause toenail infections when they enter through small cracks in the skin. People who have nail injuries, diabetes, weakened immune systems, blood circulation issues or athlete's foot have higher chances of developing toenail infections, though everyone is at risk. While toenail infections usually don't cause pain unless they are severe, they generally don't go away unless patients receive antifungal treatments such as oral prescription drugs.
People who have athlete's foot skin infections experience itching, burning, pain and skin scaling, states MedicineNet. When a fungus causes the infection, athlete's foot is contagious and can spread to other areas of the body such as the palms and groin. People can help prevent athlete's foot by not walking barefoot in areas where the fungus may be common, such as gym locker rooms and around swimming pools. At some point in their lives, up to 70 percent of people in the United States may develop athlete's foot.