back pain red flags

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Red Flags for Lower Back Pain

General Principles of Red Flags for Back Pain:

The UK Royal College of Emergency Medicine (RCEM) define Red Flags for back pain as:

  • non-mechanical back pain
  • past history of cancer, steroids, HIV
  • generally unwell
  • unexplained weight loss
  • widespread neurological symptoms or signs
  • structural deformity
  • thoracic back pain

The RCEM note the TUNA FISH mnemonic for considering red flags for back pain:

Red Flags can be considered in terms of presenting features or particular conditions

In terms of presenting features (1,2,3):

Factors in the history include:

  • cancer
  • unexplained weight loss
  • history of immunosuppression
  • history of HIV or tuberculosis
  • prolonged use of steroids
  • intravenous drug use
  • urinary tract infection
  • pain that is increased or unrelieved by rest
  • fever
  • history of atherosclerotic vascular disease
  • significant trauma related to age (e.g. fall from a height or motor vehicle accident in young patient, minor fall or heavy lifting in potentially osteoporotic or older patient or a person with possible osteopororosis)
  • bladder or bowel incontinence
  • urinary retention (with overflow incontinence)
  • consider age of patient in context of presentation of back pain - a review noted that back pain <20 years was significant (4); as is back pain in > 50 years old

Factors on examination:

  • saddle anaesthesia
  • loss of anal sphincter tone
  • major motor weakness in lower extremities
  • fever
  • vertebral tenderness
  • limited spinal range of motion
  • neurological findings persisting for more than one month
  • palpable pulsatile abdominal mass ? possible abdominal aortic aneurysm
Red Flag Symptoms with respect to possible underlying conditions:

Possible cancer red flags include:

  • history of cancer - some cancers are known to metastasise to bone
    • primary tumours which give rise to metastases to bone are remembered by many students by the nonsense rule that they all begin with a B. Thus:
      • breast
      • bronchus
      • byroid (thyroid)
      • bidney (kidney)
      • bostate (prostate)
      • (rarely, bowel)
    • however note that pancreatic cancer can present with back pain (see below)
  • unexplained weight loss
    • unintentional weight loss is loss of 10 pounds (4.5 kilograms) or 5% of your normal body weight over 6 to 12 months or less without knowing the reason (5)
  • age over 50 years
  • night pain that disturbs sleep
  • no improvement in back pain symptom in a 4-6 week period despite conservative therapy
  • back pain at rest

Possible infectious cause of back pain red flags include:

  • persistent fever
  • history of intravenous drug misuse
  • history of lumbar spine surgery within the last 12 months
  • recent bacterial infection e.g. pyelonephritis, cellulitis, pnemonia
  • history of tuberculosis
  • immunocompromised state e.g. history of use of systemic steroids, organ transplant, HIV, diabetes mellitus

Cauda Equina Syndrome Related Red Flags include:

  • urinary incontinence (occurs because of loss of sensation that passing urine)
  • urinary retention (occurs because loss of sensation of bladder fullness)
  • saddle anaesthesia
  • faecal incontinence
  • decreased anal sphincter tone
  • bilateral lower extremity weakness or numbness
  • progressive neurological deficity
    • major motor weakness - such as major motor weakness with knee extension, ankle eversion, or foot dorsiflexion.
    • major sensory deficit

Vertebral Fracture related red flags include:

  • prolonged use of systemic steroids
  • history of trauma
    • the severity of trauma where a vertebral fracture may occur varies with various factors such as age, co-morbidities and use of corticosteroids. Thus in an elderly patient with osteoporosis then a vertebral fracture might occur with minimal trauma or even after heavy lifting. In a young patient with no osteoporosis and no corticosteroid use then a vertebral fracture might occur after a significant trauma such as falling from a height onto a hard surface
  • localised vertebral tenderness
  • a structural spinal deformity e.g. a step deformity

Also consider a possible abdominal aortic aneurysm or pancreatic cancer in the patient with back pain.

AAA possible features include:

  • pulsating abdominal mass
  • past history of atherosclerotic vascular disease
  • pain at rest or nocturnal pain
  • age greater than 60 years

Pancreatic cancer possible features include (6):

  • typically patients complain of a deep epigastric pain, which in 60% of cases, radiates to the back
  • unexplained weight loss - due to anorexia or malabsorption
  • pain at rest
  • nocturnal pain


Last edited 06/2022 and last reviewed 06/2022