What is an ingrown toenail?
When a toenail is ingrown, the nail is curved downward and grows into the skin, usually at the nail borders (the sides of the nail). This “digging in” of the nail irritates the skin, often creating pain, redness, swelling, and warmth in the toe. If an ingrown nail causes a break in the skin, bacteria may enter and cause an infection in the area, which is often marked by drainage and a foul odor. However, even if your toe isn’t painful, red, swollen, or warm, a nail that curves downward into the skin can progress to an infection.
What causes an ingrown toenail?
Ingrown toenails can develop for various reasons. In many people, the tendency to have this common disorder is inherited. In other cases, an ingrown toenail is the result of trauma, such as stubbing your toe, having an object fall on your toe, or engaging in activities that involve repeated pressure on the toes, such as kicking or running. The most common cause of ingrown toenails is improper trimming. Cutting your nails too short encourages the skin next to the nail to fold over the nail. Another cause of ingrown toenails is wearing shoes that are tight or short. Certain nail conditions are often associated with ingrown toenails. For example, if you have had a toenail fungal infection or if you have lost a nail through trauma, you are at greater risk for developing an ingrown toenail.
Courtesy of the American College of Foot and Ankle Surgeons