Plain radiographs have poor sensitivity in detecting stress fractures, as positive findings may take months to appear. During the first few weeks after the onset of symptoms, x-rays of the affected area may look normal.

Positive findings include sclerosis, periosteal reaction/elevation, cortical thickening and a fracture line. Although insensitive, subtle loss of cortical density has been described as the grey cortex sign of early-stage stress injury. New periosteal bone formation may take up to 2 weeks to be detectable.