What is an ingrown toenail? Ingrown toenails can be very painful. The sides of the nail curl and grow into the skin. They are especially common on the big toenails but can occur on any toenail. What causes an ingrown toenail? Ingrown toenails can be caused by a number of things. Improper nail cutting, tight shoes or hosiery, a hereditary tendency, a curved nail growth pattern, a fungal infection, or an injury to the nail can all cause an ingrown nail. Signs of an Infected Ingrown Toenail If you see puffiness, redness or pus, this is an infected ingrown toenail and requires a doctors attention. An ingrown toenail that is not infected can be worked on at home. How to Treat An Ingrown Toenail Soak Start by soaking your foot in warm water with Epsom salts for about 10 minutes to soften the nail and the surrounding skin. Lift the Nail Next, slide an orangewood stick under the nail to gently lift the nail from the skin. Sometimes pulling the toenail out of the skin can leave a small inj