An ingrown toenail is a toenail with an edge that pushes into the skin and soft tissue at the side of the nail; this causes redness, swelling and pain and can lead to infection. Symptoms can be worse when you are wearing shoes that put pressure on the nail. The nail on the big toe becomes ingrown more often than other toenails. Ingrown toenails can be caused by cutting toenails improperly, by wearing shoes that fit poorly, or by injuring the nail bed. There is a minor office procedure that offers permanent corrections.