Q: What are ingrown toenails? A: These almost always occur on the big toe, and can cause significant pain, as well have the potential for infection. Causes can include tight shoes, poor or improper nail care, and genetic predisposition. Treating ingrown toenails involves clearing up any infection that might be present and removing the part of the nail that is growing into the toe. Having a podiatrist do it, under local anesthesia, if necessary, is the best way. To avoid ingrown toenails, cut your toenails regularly straight across instead of rounding the corners or edges, and wear shoes that have adequate width and depth, and are not too tight.