What causes a nail to become ingrown?
Ingrown toenails occur most commonly as a result of trimming toenails improperly. Rounding the edges of toenails instead of cutting them straight across creates areas that may later grow into skin. Shoes that are too tight, especially in the toe box, can also encourage curved nail growth into the skin. A person’s posture, gait, and any structural abnormalities of the feet (hammertoes, bunions, and foot pronation) may also affect one’s tendency to develop ingrown toenails. Having broken, brittle toenails may leave you with sharp nail edges that can grow into skin.