Swollen buttocks and uncomfortable sitting for a long time, the possible clinical causes are buttock soft tissue infection, pyriformis syndrome, trauma, spinal problems and so on. 1. Buttock soft tissue infection: when the buttock soft tissue is infected by bacteria, viruses and other pathogenic bacteria, the local inflammatory reaction is prone to pain, swelling and other symptoms, and the epidermal temperature will rise significantly, and in severe cases, generalized fever will occur. 2. Piriformis syndrome: this condition refers to acute and chronic injuries, or their own anatomical susceptibility to injury, and the emergence of injurious inflammatory changes, will stimulate or compress the peripheral nerves, the main clinical manifestations of buttock pain. 3. Trauma: When the hip is hit or struck by external forces, sedentary will cause further damage to the muscle tissues, which will cause pain and discomfort in the hip. 4. Spinal problems: when the spine, especially the lumbar spine, has lesions, such as herniated discs, etc., the herniated discs will be aggravated after sitting for a long time, and the compression of the nerves will lead to swelling and discomfort in the buttocks. If there are such symptoms, it is recommended to go to the hospital as soon as possible to improve the examination, clear diagnosis and then follow the doctor’s instructions for treatment, so as not to delay the condition.