There are a variety of ominous processes that cause low back pain, particularly in older patients (> 50). These problems carry significant morbidity and mortality and mandate a focused and rapid evaluation (including lab and imaging studies) different from what is required for the relatively benign processes described above. Careful history taking and examination can help distinguish these problems. Historical keys include:
- Pain that doesn’t get better when lying down/resting.
- Pain associated by systemic symptoms of inflammation (e.g. fever, chills), in particular in those at risk for systemic infection that could seed the spinal area (e.g. IV drug users, patients with bacteremia).
- Known history of cancer, in particular malignancies that metastasize to bone (e.g. prostate, breast, lung).
- Trauma, particularly if of substantial force.
- Osteoporosis, which increases risk of compression fracture (vertebrae collapsing under the weight they must bear). More common as people age, women > men.
- Anything suggesting neurological compromise. In particular, weakness in legs suggesting motor dysfunction. Also, bowel or bladder incontinence, implying diffuse sacral root dysfunction. Note: it can sometimes be difficult to distinguish true weakness from motor limitation caused by pain.
- Pain referred to the back from other areas of the body (e.g. intra-abdominal or retroperitoneal processes). Could include: Pyelonephritis, leaking/rupturing abdominal aortic aneurysm, posterior duodenal ulcer, pancreatitis, etc.