The right side of the tailbone has a tendon pain may be sedentary, overwork and other physiological factors, or to consider the lumbar muscle strain, lumbar dorsal musculoskeletal inflammation and other diseases. 1. Physiological factors: If you are sedentary and overworked for a long time, it may lead to impaired local blood circulation and pain in the right side of the tailbone. This kind of situation is a normal phenomenon, no need to worry, generally can be relieved after resting for a period of time. 2. Lumbar muscle strain: lumbar muscle strain may be caused by unhealed lumbar injury, inflammation, long-term weight-bearing, lumbar congenital deformity and other factors. Patients may experience recurrent lumbar pain and swelling, which is manifested as a tendon pain on the right side of the tailbone. 3. Lumbar dorsal myofasciitis: the cause of lumbar dorsal myofasciitis is not yet clear, it may be caused by muscle strain, trauma, long-term improper posture, environmental humidity and other factors. Patients may experience low back pain, pressure pain, stiffness and other symptoms, and some patients may experience a tendon pain on the right side of the tailbone. There are many reasons that lead to the right side of the tailbone with a tendon pain, and patients are advised to find out the cause of the disease in time.