There are four main reasons for back pain: 1. It is possible that the back muscles, tendons, ligaments and other soft tissues are strained, or that external collisions lead to injury to the scapulae and ribs and soft tissues of the back, which can locally stimulate the nerves and cause painful sensations. 2. It is possible that the soft tissues are strained, such as frequent low head ambulation or cold back, elbow joint suspension for too long. The back muscles will continue to be tense, fatigue gradually form strain, will form a sterile inflammatory lesion, stimulate the peripheral nerve, the same pain sensation. 3, may be the duodenal bulb after the ulcer, this condition is most often seen in fasting and night sleep, because then the stomach is more empty, stomach acid on the ulcer site stimulation is greater, therefore, easy to appear back pain sensation. This is because the posterior back is located behind the duodenal bulb and is innervated by the same spinal cord segment, so it is easy to have this involvement pain.4. It may be due to cholecystitis, after the formation of cholecystitis, it is easy to have a painful sensation in the right side of the back, caused by involvement pain.