Generally speaking, a little pain in one buttock bone may be caused by sciatic node cyst lesion, hip joint disease, pyriformis syndrome and so on. 1. Sciatic node cystic lesion: cystic mass can be touched in the sciatic node, the pressure pain is more obvious, and there can be a little pain in one side of the buttock bone. There is a certain degree of mobility, and the boundary range is relatively clear. 2. Hip joint diseases: such as hip osteoarthritis, hip dysplasia, femoral head necrosis, acetabular impingement syndrome. Due to the inflammation and the stimulation of the lesion site, there can be pain at the point of one side of the hip bone. 3. Piriformis syndrome: because of cold stimulation, trauma, repeated squatting and exertion caused by edema inflammation of the piriformis muscle, so that the inflammation can stimulate the sciatic nerve produced by the pain symptoms, the phenomenon of one side of the buttock bone a little pain. In addition, one side of the buttock bone a little pain can also be seen in other diseases. It is recommended that patients go to the hospital in time to avoid delay.