Snapshot A 46-year-old man presents to his primary care physician with lower back pain. His symptoms began approximately 3 weeks ago and has not subsided. The pain does not radiate, and he cannot recall what caused this. He endorses having night sweats and unexpected weight loss. He denies illicit drugs use and does not smoke. On physical exam, no saddle anesthesia, muscle weakness, or sensory changes are noted. An erythrocye sedimentation rate and prostate-specific antigen is elevated. Radiography of the lumbar spine demonstrates a compression fracture of the lumbar spine. (Metastatic prostate cancer leading to lower back pain) Introduction Definition lower back pain acute 0-4 weeks subacute 4-12 weeks chronic ≥ 12 weeks Epidemiology Incidence a very common primary care complaint Risk factors activity (e.g., heavy lifting) sedentary lifestyle psychosocial stressors (e.g., anxiety, depression, and stress) increasing age Etiology Mechanical lumbar strain degenerative disease spondylolisthesis herniated disc spinal stenosis spinal fractures Nonmechanical malignancy multiple myeloma spinal cord tumors retroperitoneal tumors infection osteomyelitis paraspinous or epidural abscess associations: fever, back pain, elevated ESR/CRP, IV drug use, immunosuppression discitis focal back pain MRI with edema seen at intervertebral discs inflammatory arthritis ankylosing spondylitis reactive arthritis inflammatory bowel disease Differential meralgia paresthetica (entrapment of the lateral femoral cutaneous nerve) numbness, tingling, and pain of the anterolateral thigh common in pregnancy Presentation Symptoms/physical exam patients present with lower back pain; however, associated symptoms depend on the cause of back pain e.g., disc herniation can lead to sensory changes in the affected dermatome Red flag findings bowel and bladder incontinence saddle anesthesia neurological findings night sweats, fever, and weightloss Imaging Radiographs indications patients at risk for malignancy with an elevated erythrocyte sedimentation rate patients at risk for vertebral compression MRI indication in patients with neurological deficits in patients with a fever, history of intravenous drug use, and immunosuppression Studies Erythrocyte sedimentate rate in cases where there is suspicion for an inflammatory or infectious cause of back pain Treatment In the absence of 'red-flag' symptoms, treat conservatively NSAIDs/acetaminophen and activity continuation physical therapy avoid bed-rest Otherwise, treatment is dictated by cause of pain