Back pain is a common clinical complaint, affecting approximately 80% of individuals at some point in their lives. It is the second most common cause of absenteeism from work after the common cold. While musculoskeletal issues are often the primary cause, back pain can also indicate serious visceral, vascular, or neoplastic conditions.

Potential causes of back pain

• Musculoskeletal (Spondylogenic): Lumbar strain, disc herniation, spinal stenosis, spondylolisthesis, ankylosing spondylitis.

• Genitourinary: Pyelonephritis, renal colic, renal tumors, hydronephrosis.

• Gastrointestinal: Pancreatitis, perforated peptic ulcer, appendicitis (especially retrocecal), cholecystitis.

• Gynecologic: Endometriosis, ectopic pregnancy, pelvic inflammatory disease.

• Vascular: Abdominal aortic aneurysm (AAA).

• Neoplastic: Multiple myeloma, metastatic tumors (e.g., prostate, breast, lung), chordoma.

Pain characterization

Characterization of pain is critical for identifying the underlying cause:

Emergency presentation and management

Back pain may reflect emergent conditions requiring urgent intervention.

Initial emergency assessment

• History: Onset, character, radiation, relieving/aggravating factors, associated symptoms.

• Vitals: Fever, tachycardia, hypotension.

• Systemic Review: GU, GI, gynecologic, neurologic symptoms.

Signs of Emergency Conditions:

• Epigastric pain radiating to back → Pancreatitis, perforated ulcer.

• Sudden tearing pain with hypotension → Ruptured AAA.

• Urinary retention, fecal incontinence, saddle anesthesia → Cauda equina syndrome.

Initial emergency interventions

• NPO (nothing by mouth).

• Oxygen and IV fluids.

• Monitor hemodynamic status.

• Pain management.

• Prepare for urgent imaging (CT, ultrasound, X-ray).

History and physical examination

history taking

• Chief Complaint: Onset, location, radiation, duration, quality, severity.

• Associated Symptoms: Weight loss, fever, neurological signs, urinary/bowel issues.

• Past Medical History: Known malignancy, recent infections, spinal trauma.

• Drug History: Especially corticosteroids, anticoagulants.

• Family History: Spinal disorders, cancer.

Physical examination

• Inspection: Gait, posture, spinal alignment.

• Palpation: Local tenderness, paraspinal muscle spasm.

• Percussion: CVA tenderness (renal origin).

• Range of Motion: Restricted in mechanical causes.

• Neurological Exam:

  • Motor: Foot drop, weakness in big toe extension (L5), plantar flexion (S1).

  • Sensory: Dermatomal loss.

  • Reflexes: Knee (L4), ankle (S1), Babinski's.

  • Special Tests: Straight leg raise, heel-toe walking, rectal tone (if cauda equina suspected).

Differential diagnosis

A. Vascular

• Abdominal Aortic Aneurysm (AAA): Sudden severe back pain, hypotension, pulsatile mass, elderly.

B. Gastrointestinal

• Pancreatitis: Epigastric pain radiating to back, nausea, vomiting, Cullen's or Turner's signs.

• Perforated Peptic Ulcer: Sudden severe epigastric pain, board-like rigidity, absent bowel sounds.

• Appendicitis (Retrocecal): Right lower quadrant/back pain, anorexia, fever.

• Cholecystitis: RUQ pain radiating to back or shoulder, Murphy's sign, fever.

C. Genitourinary

• Pyelonephritis: Flank pain, CVA tenderness, fever, dysuria, chills.

• Renal Colic (Urolithiasis): Severe colicky flank pain radiating to groin, hematuria, restlessness.

D. Spinal and Musculoskeletal

• Lumbar Strain: Localized pain, worsened by activity, no neurological signs.

• Disc Herniation: Radicular pain, worse with sitting/standing, positive SLR.

• Ankylosing Spondylitis: Young males, morning stiffness, HLA-B27.

• Spinal Tumors (e.g., Chordoma): Night pain, weight loss, neurological deficits.

E. Neoplastic

• Metastatic Cancer (e.g., Prostate, Breast): Persistent pain, nocturnal symptoms, systemic signs.

• Multiple Myeloma: Bone pain, anemia, renal failure, lytic lesions on imaging.

F. Gynecological

• Endometriosis: Cyclical lower back/sacral pain, dysmenorrhea, dyspareunia.

• Ectopic Pregnancy: Pelvic/back pain, missed period, positive pregnancy test, hypotension.

Red flags requiring immediate referral

• Age <20 or >50 with new-onset back pain.

• History of malignancy.

• Unexplained weight loss or fever.

• Neurologic deficits: incontinence, foot drop, saddle anesthesia.

• Night pain or constant, non-mechanical pain.

• Immunosuppression.

• History of trauma or known osteoporosis.

Conclusion

A thorough approach to back pain requires careful consideration of musculoskeletal, visceral, and systemic causes. Emergency conditions must be promptly recognized and addressed. Detailed history, physical examination, and early imaging are crucial for proper management and optimal outcomes.

References:

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