Ingrown toenail is a sign of ingrown toenail and is often caused by improper trimming of the toenail, for example, when trimming the toenail, the end is not cut flush so that there are small sharp edges, when the toenail continues to grow the sharp points will pierce into the flesh and cause ingrown toenail and pain next to the nail bed. Some people get toe injuries during sports or have their toes hit by hard objects, which can cause the toenail to deform and pierce the tissue next to the nail bed, and when the toenail continues to grow, it can also show up as an ingrown toenail. There are also factors such as fungal infections in the foot that can lead to deformed toenail growth and ingrown toenails.