Serious pathology in the absence of an obvious cause (e.g. trauma) is very rare, but be aware of signs suggestive of more serious pathology (red flags).

  • Symptom suggestive of cauda equina syndrome (compression of the cauda equina):
    • loss of bowel control (faecal or flatus incontinence) and unexpected laxity of anal sphincter
    • loss of bladder control (urinary retention or incontinence)
    • severe or progressive neurological deficit in the lower extremities or gait disturbance
    • saddle anaesthesia or paraesthesia (loss or change of perianal and perineal sensation)
  • Significant symptoms that may suggest cancer:
    • new onset pain in patient over age 50 years (defined as over age 55 years in some guidelines), or younger than age 20 years
    • incidence of pain in adolescents is becoming increasingly common; epidemiological surveys show point prevalence rates of around 30%
    • history of cancer
    • failure to improve after one month
  • Other symptoms that may suggest cancer include:
    • persistent night pain (unrelieved by change in position)
    • structural deformity of the spine
    • pain at multiple sites
    • unexplained weight loss
  • Symptoms that may suggest infection:
    • fevers
    • chills, rigors
    • immuno suppression
    • intravenous (IV) drug misuse
    • recent bacterial infection
    • penetrating wound
  • Symptoms that suggest fracture:
    • sudden onset of back pain associated with major trauma or minor trauma in people with osteoporosis or in those taking corticosteroids
    • structural deformity of the spine
    • severe central pain, relieved by lying down
  • Red flags may also be indicated by:
    • sensory or motor loss
    • history of serious injury
    • patients with or at high risk of osteoporosis
  • Other disorders which increase the chance of serious aetiology, eg:
    • substance abuse
    • prolonged use of corticosteroids
    • immuno suppression
    • HIV

NB: Be aware that some red flags have very high false positive rates and as such have little diagnostic value in primary care settings. Careful clinical judgment to decide whether to investigate further or referral is needed.

References:
Airaksinen O, Brox JI, Cedraschi C. European guidelines for the management of chronic non-specific low back pain. Brussels: European Commission Research Directorate General;2005.
Chou R, Qaseem A, Snow V et al. Diagnosis and treatment of low back pain: a joint clinical practice guideline from the American College of Physicians and the American Pain Society. AnnIntern Med2007;147:478-91.
Clinical Guidelines for the Management of Acute Low Back Pain. Royal College of General Practitioners, 2001.
Clinical Knowledge Summaries (CKS). Back pain - low (without radiculopathy). Newcastle upon Tyne: CKS; 2009.
van Tulder M, Becker A, Bekkering T et al. European guidelines for the management of acute nonspecific low back pain in primary care. COSTActionB13.Brussels:European Commission Research Directorate General;2004.
Welsh Backs desk aid - Management of acute low back pain