Red and yellow flags for guiding imaging of lower back pain

Lower back pain (also known as lumbago) is very common and often referred for imaging, with the vast majority of cases due to benign self-limiting causes which don't require imaging and resolve with conservative measures. Numerous authors have described various methods for supporting appropriate imaging for the investigation of lumbar back pain. One such system utilizes the idea of red flags and yellow flags.

Red flags

Red flags are patient signs, symptoms or history that indicate possible serious pathology and hence support the decision to image the lower back. If no red flags are present, there is a negligible risk of serious pathology and the patient can be reassured that imaging is not indicated and treated with conservative measures.

Red flags include:

• recent significant trauma
• unexplained weight loss
• fever
• age <20 or >55 years
• thoracic pain
• pain worse at night or at rest
• severe or progressive sensory or motor disturbance
• bladder or bowel dysfunction
• history of malignancy
• history of immune compromise
• intravenous drug use
• osteoporosis
• (prolonged) glucocorticoid use

Yellow flags

Yellow flags are psychosocial patient factors that although not associated with serious organic pathology nonetheless indicate an increased likelihood of chronic back pain and resultant long term disability and potential loss of work.

Yellow flags include:

• a belief that pain and activity is harmful or severely disabling
• fear-avoidance behavior
• sickness behaviors
• low mood
• social withdrawal
• an expectation that passive treatment rather than active participation will help
• issues with compensation system
• poor job satisfaction
• difficulty at work
• overprotective family
• lack of social support
• financial problems