My 16-year-old son is a long-distance runner and he came home complaining of a lot of pain in his foot. The doctor took some x-rays and said that his foot was fine, just to take it easy for a while. A couple of weeks later, his foot was hurting more and we took him to a different clinic where the doctor used an MRI to diagnose a stress fracture, caused by his running. We’re angry it wasn’t diagnosed the first time. How could that be missed?

Stress fractures are breaks in the bone that are caused by overuse. They typically occur in athletes or dancers, who put a lot of pressure on their feet and legs, although a stress fracture could occur anywhere.

The thing about stress fractures is they are not always easy to see on x-rays. In the early stages, they may not be visible at all. It could take between six to 10 weeks for a stress fracture to be seen by x-ray. There are other ways to diagnose, including magnetic resonance imaging (MRI) and bone scans, but they are costly and, in the case of a bone scan, invasive. If the symptoms your son showed didn’t cause the first doctor to suspect a stress fracture and the x-ray didn’t show one, it isn’t surprising that the fracture was missed.