Back Pain

Back pain is a common complaint among the general population and is mostly self-limiting. Back pain can be classified as acute, subacute, or chronic depending on the duration of symptoms. The wide variety of potential etiologies include degenerative, mechanical, malignant, infectious, rheumatologic, and extraspinal causes. A thorough history and physical examination is necessary to guide the diagnosis. Additional workup is not required unless evidence of severe diseases exists (e.g., neurologic deficits, urinary/fecal incontinence, infectious symptoms, or malignancy). Management varies depending on the cause, but most cases are managed with conservative measures and analgesics.

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Epidemiology and Etiology


Back pain is a common complaint among adults:

  • A majority of adults will develop back pain in their lifetime.
  • The most common musculoskeletal problem globally
  • A leading cause of disability

Risk factors

  • Obesity
  • Age
  • Women
  • Smoking
  • Occupation (e.g., strenuous activity, sedentary work)
  • Psychological (e.g., somatization, anxiety, depression)


  • Nonspecific back pain (most common): lacks an underlying condition
  • Mechanical:
    • Muscle strain
    • Vertebral compression fracture
    • Disc herniation
    • Spondylolisthesis (displacement of a vertebra forward in relation to the vertebra below)
    • Scoliosis and hyperkyphosis
    • Sacroiliac joint dysfunction
  • Degenerative:
    • Spondylosis (a nonspecific term for degenerative changes of the spine)
    • Osteoarthritis
    • Radiculopathy (dysfunction of the spinal nerve root from inflammation, compression, or damage)
    • Spinal stenosis
    • Cauda equina compression
  • Infections:
    • Epidural abscess
    • Discitis
    • Vertebral osteomyelitis
  • Malignancy:
    • Spinal tumors
    • Metastatic cancer
  • Rheumatologic:
    • Ankylosing spondylitis
    • Reactive arthritis
    • Psoriatic arthritis
    • Enteropathic spondyloarthropathy
    • Fibromyalgia
  • Extraspinal causes:
    • Psychological stress
    • Pancreatitis
    • Nephrolithiasis
    • Pyelonephritis
    • Abdominal aortic aneurysm
    • Herpes zoster

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Clinical Presentation


Back pain is classified based on the duration of symptoms:

  • Acute: symptoms < 4 weeks
  • Subacute: symptoms 4–12 weeks
  • Chronic: symptoms > 12 weeks


  • Pain characteristics:
    • Location
    • Onset and duration
    • Time of day
    • Pain quality
    • Severity
    • Radiation
    • Exacerbating and relieving factors
  • Associated symptoms:
    • Numbness
    • Paresthesia
    • Claudication
    • Muscle weakness
    • Gait instability
  • Review of systems (list is not exhaustive):
    • Unintentional weight loss → malignancy
    • Fever or chills → infection
    • Rash → herpes zoster
    • Bowel or bladder incontinence → spinal cord compression
    • Flank pain and urinary symptoms → urinary tract infection or nephrolithiasis
  • Recent trauma
  • Past medical history:
    • History of back pain
    • IV drug use
    • Malignancy
    • Rheumatologic disease
    • Osteoporosis
    • Corticosteroid use and immunosuppression
    • Recent bacterial infection
    • Spinal or epidural procedure
    • Disability
    • Social or psychological distress


Important, open-ended questions to ask when evaluating an individual with pain can be remembered with OPQRST mnemonic:

  • O: onset
  • P: provocation and palliation
  • Q: quality of the pain
  • R: radiation (or region)
  • S: severity
  • T: timing

Physical examination

General examination:

  • Inspection:
    • Posture
    • Deformities
    • Erythema
    • Rash
  • Palpation of the spine and paraspinal muscles:
    • Tenderness
    • Muscle tone
    • Swelling
    • Asymmetry
    • Masses
  • Range of motion (ROM):
    • Flexion
    • Extension
    • Side bending
  • Neurological examination to assess the entire spinal cord:
    • Deep tendon reflexes (DTR)
    • Strength testing
    • Sensation (dermatomal distribution)
    • Gait

Specific maneuvers:

  • Straight leg-raising test:
    • Lay the individual supine and test both legs.
    • The extended leg is passively raised with the foot dorsiflexed.
    • Result: increased lower-lumbar tension and high sacral-dural tension
    • A positive test elicits worsening radicular pain down the raised leg.
    • Evaluates for lumbosacral radiculopathy (sciatica)
  • Patrick test:
    • Lay the individual supine and instruct to place 1 foot on the opposite knee.
    • The contralateral hip is supported by the examiner and downward pressure is placed on the flexed knee.
    • A positive test elicits pain in the sacroiliac joint.
    • Indicative of potential sacroiliac joint pathology

Signs and symptoms of a red flag

The following symptoms suggest serious pathology and should elicit an urgent evaluation:

  • Neurologic deficits:
    • Muscle weakness
    • Gait disturbance
    • Saddle anesthesia
    • Bowel or bladder dysfunction
  • Fever
  • Unexplained weight loss
  • Severe nocturnal back pain



The majority of individuals with back pain do not require imaging.


  • Acute trauma
  • Signs or symptoms of a red flag
  • High clinical suspicion of infection or malignancy:
    • Diagnosed or suspected cancer
    • Risk factors for infection:
      • Immunosuppression
      • IV drug use
      • Recent surgery
      • Penetrating trauma
      • Bacterial infection
  • High clinical suspicion for life-threatening conditions:
    • Acute, tearing pain in the upper or middle back
    • Abdominal aorta > 5 cm (especially if tender) or lower extremity pulse deficits
    • Gastrointestinal findings:
      • Peritoneal signs
      • Abdominal tenderness
      • Melena
      • Hematochezia
  • Disabling pain

Imaging modalities:

  • Plain radiograph:
    • Anteroposterior and lateral views are adequate.
    • Useful for assessing:
      • Osteoporotic or compression fractures
      • Lytic bone lesions (malignancy)
      • Spondylolisthesis
      • Malignment 
      • Osteoarthritis
      • Loss of disc height
  • MRI:
    • Best initial evaluation for individuals requiring advanced imaging
    • Helpful in evaluating:
      • Ligaments
      • Intervertebral discs
      • Nerve roots
      • Shape and size of the spinal canal
      • Spinal cord
    • Specific and sensitive for malignancy and infection
  • CT scan is an option for those who cannot undergo MRI.

Laboratory studies

  • Most individuals do not require lab studies.
  • Erythrocyte sedimentation rate (ESR), CRP, and CBC can be useful if an inflammatory or infectious etiology is suspected.


Conservative measures

  • Education and reassurance
  • Heat or cold packs
  • Massage
  • Exercise and physical therapy
  • Posture improvement
  • Acupuncture
  • Spinal manipulation

Pharmacologic management

  • Initial therapy:
    • NSAIDs
    • Acetaminophen
  • 2nd-line therapy: muscle relaxants:
    • Controversial
    • Sedating (particularly in the elderly)
    • More helpful with an associated muscle spasm
    • Ideally only used for short-term therapy
  • Severe or refractory pain:
    • Opioids and tramadol
    • Only added to therapy when other analgesics fail or are contraindicated
    • Can cause sedation, constipation, and dependence
    • Avoid long-term use.

Glucocorticoid injections

  • May be helpful when conservative therapy and analgesics have not been effective
  • Injection options:
    • Epidural
    • Facet joint
    • Local or trigger point
    • Sacroiliac joint

Surgical treatment

  • Only required in a minority of individuals
  • Indications:
    • Refractory, disabling symptoms
    • Severe or progressive weakness
    • Cauda equina syndrome
    • Infection (e.g., epidural abscess)

Clinical Relevance

  • Cauda equina syndrome: compression of nerve roots of the lumbar spine. Intervertebral disc herniation is the most common cause. Other causes include ankylosing spondylitis, lumbar puncture, trauma, malignant/benign tumor, and infection. Individuals will have back pain, lower extremity weakness, sensory findings (such as saddle anesthesia), and bowel/bladder dysfunction. In addition to the physical examination, imaging will help to confirm the diagnosis. Surgery is required to relieve compression of the nerve roots.
  • Metastatic cancer: Bones are common sites for metastases. Vertebral involvement may cause back pain and sudden, severe pain may indicate a pathologic fracture. Compression of the spinal cord or nerve root can occur. The diagnosis can be made with MRI. Management depends on the cancer, location, and severity of symptoms. Palliative care is often recommended.
  • Spinal epidural abscess: pus accumulation within the spinal epidural space. Individuals may experience fever, malaise, and localized back pain (often worse laying down). If left untreated, neurologic deficits can occur due to compression of the spinal cord or nerve roots. Diagnosis is made with MRI. Treatment includes antibiotics and aspiration of the abscess. Surgery is necessary for individuals with neurologic dysfunction.
  • Vertebral osteomyelitis: vertebral infection occurring due to hematogenous spread, direct inoculation, or contiguous spread from adjacent soft tissue. The major clinical symptom is localized pain exacerbated by physical activity or percussion at the affected site. The preferred imaging modality for diagnosis is MRI. Treatment includes antibiotics. Surgery may be needed for spinal instability, neurological deficits, cord compression, or worsening/persistent infection.
  • Vertebral compression fracture: often caused by trauma or osteoporosis. The presentation includes pain, which is often radiating. Movement aggravates the pain and may be accompanied by muscle spasms. The diagnosis is made with imaging. Management is usually conservative (physical therapy and analgesics) unless evidence of associated spinal cord injury exists.
  • Spinal stenosis: a narrowing of the central canal, the neural foramen, or the lateral recess. Degenerative changes, spondylolisthesis, disc herniation, tumors, and fractures may cause spinal stenosis. While some individuals are asymptomatic, others may experience back pain, neurogenic claudication, weakness, and numbness. Diagnosis is clinical and confirmed with imaging. Management includes physical therapy and analgesics. Surgery is reserved for advanced cases.


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