Lateral thigh and buttock connection pain consider local muscle injury, lumbar intervertebral disc herniation, pyriformis syndrome leading to sciatic nerve entrapment and so on. 1. Trauma or prolonged exercise: it can lead to local muscle strain or strain injury of the thigh and buttocks, causing local edema, oozing, and gathering of inflammatory factors, resulting in pain in the connection between the outer thigh and buttocks. 2. Herniated lumbar intervertebral disc: it can compress the nerve roots in the lumbar region, causing throbbing pain in the buttocks and lower limbs, accompanied by numbness in the lower limbs, pain in the lumbar region, and restriction of activities. 3. Piriformis syndrome: localized compression of the sciatic nerve, or trauma resulting in contusion of the sciatic nerve, nerve edema, can occur in the buttocks and thigh joint pain, accompanied by numbness of the lower limbs, resulting in impaired mobility. There are many reasons for the pain in the connection between the outer thigh and the buttocks, and it is recommended to actively seek medical attention and treatment under the guidance of physicians.