A stress fracture occurs when the repetitive loads on a bone exceed what the bone can take, so a small crack or fracture develops in the bone. It can happen in any bone, but is more likely to happen in bones that get put under a lot of stress. The calcaneus or heel bone is one of those bones. It is the bone that runners hit the road with when running. If those repetitive loads occur too quickly and the bone is not given time to adapt or get used to the loads, then a calcaneal stress fracture might occur.
Knowing if you have a calcaneal stress fracture is based on their being pain in the heel bone – this is often deep inside the bone and there are also not a lot of other structures in the area that the pain could be in. The pain usually starts off as not much more than a mild ache that gets progressively worse with more activity.
The calcaneal stress test is usually positive. Imaging will often also show it, though it may not show up on a plain x-ray for several weeks.
There is almost always a history of activity levels or an increase in activity levels that would predispose top a calcaneal stress fracture.