From the Guidelines
Red flags for low back pain requiring immediate medical attention include signs of cauda equina syndrome, severe or progressive neurological deficits, fever or signs of infection, history of cancer, unexplained weight loss, recent trauma, age over 50 with new onset pain, osteoporosis, prolonged corticosteroid use, and pain that worsens when lying down or at night. These symptoms warrant urgent evaluation because they may indicate serious underlying conditions such as spinal cord compression, malignancy, infection, or fracture. The diagnostic workup typically includes a thorough history and physical examination, followed by appropriate imaging (MRI is often the preferred initial study) and laboratory tests based on the suspected diagnosis 1. Some key points to consider in the diagnostic workup include:
- Evaluating patients for the presence of rapidly progressive or severe neurologic deficits, including motor deficits at more than 1 level, fecal incontinence, and bladder dysfunction 1
- Considering risk factors for cancer, such as a history of cancer, unexplained weight loss, failure to improve after 1 month, and age older than 50 years 1
- Considering risk factors for vertebral infection, such as fever, intravenous drug use, or recent infection 1
- Considering risk factors for vertebral compression fracture, such as older age, osteoporosis, and prolonged corticosteroid use 1 Delaying diagnosis and treatment of these conditions can lead to permanent neurological damage, systemic infection, or other serious complications, which is why prompt medical evaluation is essential when these red flags are present. Patients experiencing these symptoms should seek emergency care rather than waiting for scheduled appointments. It is also important to note that the likelihood of cancer in patients presenting with back pain increases from approximately 0.7% to 9% in patients with a history of cancer, and that features predicting the presence of vertebral infection have not been well studied but may include fever, intravenous drug use, or recent infection 1.
From the Research
Red Flags for Low Back Pain
The following are red flags for low back pain that may indicate serious underlying conditions:
- Recent trauma or significant injury 2, 3
- Age over 50 years 4, 3
- Use of steroids or immunosuppressors 5, 3
- History of cancer 5
- Unintentional weight loss 5
- Night pain or pain at rest 5
- Fever, chills, or sweating 4
- Recent infection or immunosuppression 4
- Cauda equina syndrome (e.g., numbness, weakness, or loss of bladder/bowel control) 2, 5
Diagnostic Considerations
When evaluating patients with low back pain, it is essential to consider the presence of red flags, as they may indicate a need for immediate diagnostic workup and potential intervention 2, 4, 5. However, the absence of red flags does not necessarily rule out serious underlying conditions, and clinicians should use caution when interpreting red flag questions as screening tools 4.
Limitations of Red Flags
The diagnostic accuracy of red flags for identifying serious pathology in patients with low back pain is limited, and many red flags have high false positive rates 4, 3. Therefore, clinicians should consider the clinical context and use a combination of red flags, rather than relying on individual flags, to screen for vertebral fracture or other serious conditions 3.