Interpretation of Red Flag Findings in Patients With Back Pain

Finding

Causes to Consider

Abdominal aorta that is > 5 cm (particularly if tender) or lower-extremity pulse deficits

Abdominal aortic aneurysm

Acute, tearing upper and midback pain

Thoracic aortic dissection

Cancer, diagnosed or suspected

Metastases

Duration of pain > 6 weeks

Cancer

Subacute infection

Spondyloarthropathy

Fever

Cancer

Infection

Gastrointestinal findings such as localized abdominal tenderness, peritoneal signs (rebound tenderness or abdominal rigidity), melena, or hematochezia

Possible gastrointestinal emergency (eg, peritonitis, abscess, gastrointestinal bleeding)

Infection risk factors (eg, immunosuppression; injection illicit drug use; recent surgery, penetrating trauma, or bacterial infection)

Infection

Meningismus

Meningitis

Neurologic deficit

Nerve root or spinal cord compression

Severe nocturnal or disabling pain

Cancer

Infection

Unexplained weight loss

Cancer

Subacute infection