The main reasons for severe back pain at night are related to lumbar spine lesions, lesions of internal organs, unsuitable mattress or cold. 1. Lumbar spine lesions: If there are lumbar spine lesions, such as lumbar disc herniation or lumbar spinal stenosis, it is easy to trigger the symptoms of lumbar pain, and the symptoms of lumbar pain will be more obvious when you sleep at night after exertion during the day. 2. Diseases of internal organs: when there are kidney or pancreas and gynecological diseases, it may trigger the manifestation of lumbar radiating pain, and the pain may be more obvious at night when you sleep, and it will radiate to the front abdomen. 3. Inappropriate mattress or cold: If the mattress is too soft or too hard during the night sleep, as well as not paying attention to the back of the waist to keep warm during sleep, resulting in localized cold, may trigger symptoms of severe back pain. If the symptoms of nocturnal low back pain occur frequently, it is necessary to check and evaluate the specific causes, and then under the guidance of a professional physician, targeted treatment to prevent the aggravation of the condition later.