Flail chest is typically diagnosed during an extensive physical evaluation after a traumatic injury. A computed tomography (CT) scan is the preferred test for identifying flail chest, as an X-ray may not identify all rib fractures.
If a CT scan alone or in combination with an X-ray finds at least three ribs broke in two places, flail chest will be diagnosed.
Medical professionals will monitor for changes in breathing that could be a sign of respiratory failure from flail chest.