Stress Fracture

A stress fracture is a hairline crack that develops in bone when repeated mechanical stress overwhelms the bone's ability to repair itself. Rather than snapping from a single force, the bone sustains microscopic damage faster than it can heal — eventually resulting in a crack. Stress fractures are especially common in weight-bearing bones of the feet, shins, and hips.

You may be at higher risk if you have recently increased your activity level, train on hard surfaces, or have low bone density. Women — particularly those with irregular periods or eating concerns — can be more vulnerable because hormonal changes affect bone strength. This connection is sometimes called the female athlete triad.

Pain that worsens with activity and improves with rest is the hallmark symptom. Imaging such as an MRI or bone scan may be needed, since stress fractures often don't show clearly on standard X-rays until healing has already begun. Most stress fractures heal with rest and a gradual return to activity, and understanding your bone health can help you prevent future ones.

Stress fractures matter because ignoring the warning signs — persistent, localized bone pain — can allow a small crack to become a complete break, which takes far longer to heal and may require surgery. Catching a stress fracture early usually means a much shorter recovery.

For people with low bone density, a stress fracture can also be a signal that the underlying bone health needs attention. A conversation with your healthcare provider about bone density testing may be worthwhile, especially if you have had more than one stress fracture or if they occur with minimal activity.