Stress fractures are incomplete cracks in bone caused by overuse. They are common in athletes and those who begin an activity and go too hard, too fast. Stress fractures left untreated may become complete fractures, which require casting and immobilization.
You should rest, ice, compress, and elevate the foot or ankle until you can see a doctor. In order to make sure you don't have a break, you need to visit a doctor. If treated early, the healing process is painless and effective. The longer you wait to be treated, the longer the recovery will become.