Most back pain is not dangerous. The majority of episodes are mechanical, meaning they come from muscles, ligaments, discs or joints, and they settle within a few weeks with gentle activity, good posture and simple pain relief. However, a small number of back pain cases are warning signs of a more serious problem, and knowing these red flags can protect you from lasting harm. The most urgent red flag is a group of symptoms called cauda equina syndrome. This includes numbness in the saddle area (the inner thighs, buttocks and genitals), difficulty passing or controlling urine, loss of bowel control, or rapidly worsening weakness in both legs. These symptoms are a medical emergency and need same-day hospital assessment, because delayed treatment can cause permanent damage. Other warning signs deserve prompt medical review, though not always emergency care. These include back pain following a significant injury or fall, especially in older adults with possible osteoporosis; pain that is constant, progressively worsening and not relieved by rest or by changing position; night pain that wakes you from sleep; unexplained weight loss, fever or night sweats alongside back pain; a history of cancer; or new leg weakness, numbness or foot drop. Pain in someone with a weakened immune system, or in a person who uses intravenous drugs, also needs careful evaluation for infection. If you have back pain without any of these features, it is reasonable to stay active, avoid prolonged bed rest, use simple measures and give it a few weeks to improve. But if any red flag appears, do not wait it out. See a doctor promptly, and go to an emergency department immediately if you develop the cauda equina symptoms described above. Early assessment of true red flags is what prevents rare but serious problems from being missed.in Red Flags: Warning Signs You Should Never Ignore