Back pain is one of the most common causes for which people seek emergency care. Back pain can be relentless, causing some people to feel significantly debilitated. Back pain can affect people of any age. Mechanical back pain is the cause of 90% of cases, so health care providers can sometimes miss rare or non-specific causes while focusing on common etiologies.
 

Causes of Back Pain (Wheeler et al., 2022)

Approximately 85% or more of patients seen in primary care have non-specific low back pain. This means that the patient does not have an identifiable underlying condition as the cause of the back pain.  Many of these patients have musculoskeletal back pain, which usually improves in a few weeks. Approximately 1% of cases have a serious etiology. Most of these patients will have risk factors or other symptoms. Some of the etiologies include:

• Serious Etiologies

  • ​Spinal cord or cauda aquina compression
    • Most common cause is herniation of the intervertebral disc
    • Other causes include ankylosing spondylitis, lumbar puncture, trauma, malignant tumor, benign tumor, and infection
    • Pain is usually first symptom of cord compression
    • Motor and sensory findings are present in the majority of patients at diagnosis
    • Bowel and/or bladder dysfunction are usually late findings
  • Metastatic Cancer
    • Bone is one of the most common sites of metastasis
    • History of cancer is the strongest risk factor for back pain from bone metastasis
    • Pain is the most common symptom
    • A history of cancer and sudden, severe back pain raises concern for a pathological fracture
  • Spinal epidural abscess
    • Initial symptoms include fever and malaise (non-specific), then over time patient might develop localized back pain, then radicular pain, and if left untreated, neurological deficits
    • Immunocompromised patients are at higher risk
    • Risk factors include recent spinal injections, epidural catheter placement, injection drug use, and other infections
  • Vertebral osteomyelitis
    • Usually presents with back pain and gradually increases over months to weeks
    • Fever may or may not be present
    • Incidence increases with age, more common in males than in females
    • Linked to health care-related or post-procedural spread of bacteremia

• Less Serious Etiologies

  • Verebral compression fracture
  • Radiculopathy
  • Spinal stenosis

• Other Etiologies

  • Axial spondyloarthritis
  • Osteoarthritis
  • Scoliosis and hyperkyphosis
  • Psychological stress
  • Etiologies outside the spine