In contrast to tendinitis, in which the painful area is more diffused, if you put your finger on a stress fracture it will really hurt. So the first thing to do if you suffer any of these symptoms is look to your shoes. If you hurt only when you wear one particular pair of shoes and are fine the rest of the time, you're in luck. It's much easier to replace a pair of shoes than it is to replace a foot. If the symptoms persist no matter what shoes you wear, stop doing whatever it is that makes you hurt.
Rest is the primary treatment for stress fractures.
That and dealing with the swelling by icing and taking contrast baths. Getting into a stiff-soled shoe to reduce the movement of your foot can also help. Boots are very good in this regard. The navicular bone, which occupies a position in the foot somewhat like the keystone of an arch, and is therefore particularly vulnerable, can be fractured this way, as can the base of the fifth metatarsal. One is the result of a severe ankle sprain, which can pull off the peroneal tendon attached there.