Definition of Ingrown toenail:

An ingrown toenail occurs when the edge of the nail grows into the skin of the toe. There may be pain, redness, and swelling around the nail.

Causes, incidence, and risk factors:

An ingrown toenail can result from curved toenails, poorly fitting shoes, toenails that are trimmed improperly, or a toe injury. The skin around the toenail may become red and infected. The great toe is usually affected, but any toenail can become ingrown.

The condition may become serious in people with diabetes.