Whether a lumbar vertebra protruding backwards by 2mm is serious or not cannot be generalized, but needs to be judged according to the patient’s condition, whether there is any compression of the spinal cord and nerves, and whether there are obvious symptoms. 1. Not serious: If there is no compression of the spinal cord and nerves, and there are no obvious symptoms, a lumbar vertebra protruding backwards by 2mm is usually not serious. 2. Serious cases: If one lumbar vertebra protrudes backward by 2mm, resulting in compression of the spinal cord and nerve roots in the spinal canal, low back pain, leg pain, numbness and weakness in the legs, and sciatica, the situation is more serious. If one lumbar vertebra protrudes backward by 2mm, early standardized treatment is recommended to reduce the adverse effects of the disease.