3. Swelling
Swelling is a natural response to injury. The reason the body swells up in response to injury like this is in order to provide a supply of blood as well as other beneficial fluids to the site of the problem. Increased blood will carry more nutrients to the area, and this will also rush white blood cells and other types of immune responders. The aim for your body is to quickly section off the area, cause it to clot, and prevent infection.
At the same time, swelling may help to prevent movement of the limb.
The problem is that swelling can cause more damage if it places excess pressure on the injury, and it can certainly lead to additional pain.
Addressing swelling should not be a primary concern if you have just acquired a stress fracture. However, if you are in recovery, then your doctor might have instructed you to try and address the swelling by applying ice packs, by elevating the affected area, and by applying gentle compression with a towel or bandage.