Low back pain (LBP) is a common problem that poses some interesting and difficult diagnostic problems. It is typically benign and self-limited, but it is occasionally the presenting symptom of serious systemic disease. The general diagnostic approach to low back pain is to check for 'red flags' in the history and physical that suggest the presence of malignancy, infection or spondyloarthridites, and for neurological compromise that could indicate that surgery is required (cauda equina syndrome) or may be beneficial (such as herniated discs or spinal stenosis that have not improved with conservative care). In the absence of these features, imaging is of limited value. Recent research has begun to evaluate subgroups with 'non-specific' low back pain that seem to benefit from specific interventions such as median branch or sacroiliac joint injections, manipulation, or specific exercises, but these require further investigation and validation.