What will happen if you leave an ingrown toenail without treatment?

Any infection: If no infection willing to suffer with pain nothing will happen, if there is infection that is aseptic focus in your body, that will effect your body.

Infection of bone: Ingrown toenails can cause infection in the skin which can progress to bone infections. The skin in your toe is close to your bone so long standing ingrown toe nails are dangerous. If infection gets to your bone, there is a chance you can lose your toe.