Ingrown toenails, known as onychocryptosis, most commonly occur on the big toe and are caused by pressure that drives the edge of the nail into the surrounding skin. Ingrown toenails can result from improper nail trimming, injuries, fungal infections, and toe deformities; they can also be inherited. The condition causes pain, redness, inflammation, swelling, and sometimes, infection. The condition is common in athletes and runners and can be caused by ill-fitting footwear in the toe area.

Although ingrown toenails can go away on their own, warm foot soaks with Epsom salts, elevation, and anti-inflammatory medications may help with healing and reducing pain (always seek medical advice from a doctor before taking any medication). Ingrown toenails that are chronic, persistent or get worse should be treated by a doctor who can prescribe antibiotics or even perform surgery, if necessary, to alleviate the condition. To prevent ingrown toenails, trim the toenails straight across and avoid clipping the nails too short or in a curved fashion.