That pain at the end edge of your toenail is uncomfortable and disturbing. An ingrown toenail is when the nail grows into the skin causing pain and irritation to the skin. When the skin is broken, it poses risk to allow bacteria that can cause infections making the ingrown toenail more painful; see a doctor for ingrown toenail immediately. If you notice that you have painful, red, swollen, and hot toenails, it might be infected. Though one question sticks with you, why do you have ingrown toenails?