Summarize this article:

An infected ingrown toenail will require medical treatment or the infection may spread to the bone. Signs that an ingrown toenail might be infected include:  redness swelling warmth pus If you have diabetes or any condition where circulation is limited in your feet (such as peripheral artery disease), then you will need to see a podiatrist for regular check-ups. Seeing a podiatrist can reduce your chances of needing a foot or limb amputation by as much as 85%. If you notice that you have an ingrown toenail or if your toenail has become infected, then call a podiatrist to make an appointment for as soon as possible. If you often get ingrown nails, then surgical removal of all or part of the nail may be the best option.  Your podiatrist can perform this procedure using local anesthesia, so you will not feel anything.  If the problem keeps recurring, then it may be necessary to remove an entire section of the nail root to prevent future ingrown nails.

Summary:
Check for signs of infection. See a podiatrist regularly if you have a condition that limits your circulation. Consider surgical removal.