疲劳性骨折，又称应力性骨折，是一种不完全骨折。通常由于异常的或重复性的外界应力，或者腿部或踝部持续负重所导致。常发生于胫骨、跖骨，以及相对少见的股骨、桡骨。

疲劳性骨折是一种常见的运动伤，在运动员中常有发生。由于疲劳性骨折一般只是骨骼上非常细小的裂缝或破碎，在X光检查中通常不能看出，因此容易被漏诊或误诊。一般通过CT扫描、核磁共振成像或骨扫描对其确诊。

Stress fracture, also known as a hairline fracture, is a fatigue-induced fracture of the bone caused by repeated stress over time. Instead of resulting from a single severe impact, stress fractures are the result of accumulated trauma from repeated submaximal loading, such as running or jumping. Because of this mechanism, stress fractures are common overuse injuries in athletes.