An ingrown toenail occurs when the skin on the side of a toenail grows over the edge of the nail, or when the nail grows into the skin.
Ingrown toenails can develop for many reasons. Here are some examples:
• Toenails that are too large
• Toes that curl from arthritis
• Stubbing a toe or having one stepped on
• Frequent running
• Trimming nails incorrectly
• Excessively tight stockings
• Shoes with narrow toe boxes
Bedridden patients commonly develop ingrown toenails if the bed sheets are tucked-in tightly.