Ingrown nails -- when the nail grows into the flesh instead of over it -- usually affect the toenails, particularly the big toe. People with curved or thick nails are most likely to get them. But anyone can suffer from ingrown nails because of an injury, poorly fitting shoes, or improper grooming of the feet. People with diabetes, vascular problems, or numbness in the toes need to be aggressive in treating and preventing ingrown toenails because they can lead to serious complications, including the losing a limb.
A damaged or improperly trimmed nail can become ingrown, burrowing into the skin at the side of the nail. The site can become painful and infected, and may not heal until the nail is removed. To avoid ingrown nails, always trim nails straight across.