Over-zealous training usually causes tendonitis, especially among beginners who try to do too much too soon. A common myth among athletes, according to Crane, is that it's not possible to walk or run if a bone in the foot is fractured. That's dead wrong, especially with stress fractures when pain and swelling might not occur for a few days. Should pain and swelling continue after following this procedure for three or four days, you should see a podiatric foot and ankle surgeon for an x-ray and proper diagnosis. Black toenails happen when a blood blister forms under the nail from trauma, and it's best to let the nail fall off by itself.
Fungal toenails are yellow, brown or black and sometimes are irregularly shaped and thick.
They are best treated with oral anti-fungal medications. Runners should avoid wearing cotton socks and running without socks. Foot powders, aerosols antiperspirants and vinegar soaks also are helpful. Use a sterile instrument to lance the corner, leave the top as a biological dressing, wash, apply antibiotic ointment, and cover with a Band-aid. Corns and calluses are caused by repeated friction, and should be treated by aseptically trimming the dead skin and eliminating the underlying cause.