www.sofootankle.com The causes of an ingrown toenail can be different. You can cut your toenail the wrong way or cut into your toenail. That actually is not the most common way that ingrown toenails start that I have seen. A lot of times it’s from the toenails rubbing together in a tight shoe or kids in high school in athletics. They’ll get ingrown toenails a lot because they’re so athletic and their toes are rubbing against each other, or they bump their toe. It becomes painful because of that. You can get an ingrown toenail from something dropping on your toe, or your toenail may start to grow differently. Or you may get toenail fungus underneath your nail, and that can cause the nail to turn and cause and ingrown toenail.