Ingrown toenails are due to the penetration of the edges of the nail plate into the soft tissue of the toe. It begins with a painful irritation that often becomes infected. With bacterial invasion, the nail margin becomes red and swollen often demonstrating drainage or pus. In people who have diabetes or poor circulation this relatively minor problem can be become quite severe. In this instance a simple ingrown toenail can result in gangrene of the toe. Patients with joint replacements or pace makers are at risk of bacterial spread through the blood stream resulting in the spread of infection to these sites. These patients should seek medical attention at the earliest sign of an ingrown toenail. There are several causes of ingrown toenails: a hereditary tendency to form ingrown toenails, improperly cutting the toenails either too short or cutting into the side of the nail and ill-fitting shoes can cause them. Children will often develop ingrown toenails as a result of pealing or tearing their toenails off instead of trimming them with a nail clipper. Once an ingrown toenail starts, they will often reoccur. Many people perform “bathroom” surgery to cut the nail margin out only to have it reoccur months later as the nail grows out.

Source: Kirk A. Koepsel, D.P.M.