Lower Back Pain: Red & Yellow Flags

Each year 1:15 of the adult population will seek medical help for Lower Back Pain, that is 2.6 million patients in the UK. Most Lower Back Pain is not serious and will revolve within 8 weeks, with analgesia and self physio.

However, this is not the case for some. This may be due to serious underlying pathology ‘RED Flags‘, or psychological factors that indicate chronicity ‘Yellow Flags‘.

Red Flags: Pathology [Link-NICE]

Cauda equina syndrome:

  • Bilateral sciatica
  • Severe or progressive bilateral neurological deficit of the legs such as major motor weakness with knee extension, ankle eversion, or foot dorsiflexion.
  • Bowel/Bladder/Sexual Dysfunction
  • Saddle Anaesthesia/Paraesthesia
  • Laxity of the anal sphincter
  • CES pathway – Link HERE

Spinal Fracture:

  • Traumatic mechanism
  • Minor trauma or strenuous lifting – in people with osteoporosis or those who use corticosteroids.
  • Deformity of the spine
  • Point tenderness – over a vertebral body.
  • Sudden onset of severe central spinal pain (relieved by lying down)


  • Age: >50 years
  • Gradual onset of symptoms.
  • Severe unremitting pain – remains when the person is supine
  • Night pain – that prevents or disturbs sleep
  • Pain aggravated by straining – Pooing/Coughing/Sneezing
  • Thoracic pain
  • Localised spinal tenderness
  • No improvement after 4-6 weeks – of conservative therapy
  • Unexplained weight loss
  • Past history of cancer — breast, lung, gastrointestinal, prostate, renal, and thyroid cancers are more likely to metastasize to the spine.


  • Fever
  • Tuberculosis, or recent urinary tract infection.
  • Intravenous drug use
  • Immunocompromised – HIV infection, use of immunosuppressants, Diabetes

Under 16 years old:

Back pain is less common in the paediatric population, and its more likely to be pathological. Hence children presenting with back pain need a very careful history and examination, often with senior input. Link HERE

  • Mechanical
    • Spondylolysis (unilateral fracture of the pars interarticularis) -common injury in hyperextension
    • Scheuermann disease – late childhood, kyphosis, gradual, X-ray
  • Cancer
    • Localised back pain, weight loss, night time pain, progressive
  • Infection
    • Discitis – Symptoms often non-specific; fatigue, irritability, limp, refusal to sit or walk. Localizing symptoms and fever are infrequent. WCC is often normal, but CRP is typically elevated, can be seen on MRI.
    • Pyogenic sacroiliitis – more common in Teenagers, IVDU, skin infection. Often pain increased by hip felx/abduction, <50% will have fever.WCC is often normal, but CRP is typically elevated, can be seen on MRI.
    • Spinal tuberculosis (Potts disease) – think about recent travel or exposure.
  • Autoimmune
  • Arthritis

Red Flag – Investigation

Investigation of Red-Flag symptoms need to be tailored to the suspected diagnosis. In some situations e.g. CES/Fracture/Infection as an Emergency but as a minimum Urgently (e.g. 2 week wait either directly through clinic referral or via GP). Potential investigations include

  • Radiology: MRI, CT, Xray
  • Bloods: FBC, Bone profile, U&E, LFT, CRP, Myeloma screen, Cultures

Yellow Flags: Psychological indicators of chronicity

The following factors have been shown to be indicators that “Simple” back pain may becoming a chronic issue for the patient. As part of our discharge if we can try and address these issues it may prevent an acute issue becoming a chronic problem. [Link HERE]

  • Negative attitude that back pain is harmful or potentially severely disabling Explain that moving even though painful is helpful not harmful
  • Fear, avoidance behaviour and reduced activity levels 
  • Expectation that passive, rather than active, treatment will be beneficial
  • Tendency to depression, low morale, and social withdrawal
  • Social or financial problems

The Back Book from the RCGP is recommended – Link HERE

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