Pain in the right back muscles occurs for the following reasons: first, collateral dorsal myofasciitis, that is, aseptic inflammation of the white fascia on the surface of the back muscles, so pain commonly occurs in the supraspinatus, infraspinatus, trapezius, latissimus dorsi muscles and other muscles with aseptic inflammation. Second, rheumatic polymyalgia, if the age is over 50 years old and male, and there is pain in the back muscles, and the laboratory blood sedimentation is >50mm/h, then it can be diagnosed as rheumatic polymyalgia. Third, fibromyalgia syndrome, women who present with right posterior back pain should consider fibromyalgia syndrome, in addition to other areas of pressure pain can also help the diagnosis. Fourth, right posterior back muscle pain can sometimes be caused by internal diseases, such as pleurisy, lung tumor, cholecystitis, hepatitis, etc. Attention should be paid to the identification by a professional doctor.