An ingrown toenail (also known as paronychia or onychocryptosis) occurs when the nail grows sideways into the toe instead of outward, resulting in pain of the nail fold. It can be caused by any situation that interferes with the proper outward growth of the nail, such as improper trimming of the nail or incorrect footwear.
The diagnosis of an ingrown toenail can be made on the basis of the appearance of the toe. A history of the condition is also obtained to determine the cause of the ingrown toenail and to address any predisposing circumstances.
In most cases, the edge of the nail can be separated from the side of the toe. Padding is the placed between the nail and the toe to encourage growth in the correct direction. Many cases require surgical removal of the toenail. A new, normal nail then grows in over the next several months.
The nail may continue to grow into the side of the toe. This can lead to worsening pain or recurring infection, but is most serious in people with underlying medical problems such as diabetes or peripheral vascular disease.