Ingrown toenails happen when the edges of the nail grow into your skin. They cause pressure and pain along the nail edges. The edge of the nail may cut into your skin, causing redness, swelling, pain, drainage, and infection. The most common cause of ingrown toenails is pressure from shoes. Other causes include improperly trimmed nails, crowding of the toes, and repeated trauma to the feet from activities such as running, walking, or doing aerobics. Keep your toenails properly trimmed to prevent ingrown toenails. If you have a persistent problem or If you have a nail infection, you may need a doctor’s care. Surgery to remove part of the toenail and growth plate can treat severe problems from ingrown toenails.