The causes of thigh root pain may be bone and joint diseases, inguinal lymphadenitis, chronic pelvic inflammatory disease, tumors, chronic strain, etc. The symptoms may vary according to the cause. 1. Bone and joint diseases: synovitis of the hip joint, osteoarthritis of the hip joint, pyriform myositis, necrosis of the femoral head, etc., which may lead to pain at the root of the thigh, and may be accompanied by limited mobility and swelling of the hip joint. 2. Inguinal lymphadenitis: In addition to thigh root pain, it may be accompanied by swelling and tenderness of inguinal lymph nodes, local skin redness and edema, often accompanied by fever and chills. 3. Chronic pelvic inflammatory disease: in addition to thigh root pain, there may be pain in the lower abdomen, swelling, lumbosacral pain and so on. 4. Tumor: primary tumor or metastatic tumor of femur may lead to thigh root pain, swelling, activity limitation and so on, and there may be systemic symptoms such as emaciation in the later stage. 5. Chronic strain, soft tissue injury: keeping a movement or external force for a long time may lead to thigh root pain, which is usually accompanied by soreness and swelling of thigh. There are many reasons for thigh root pain, if it is difficult to relieve, it is recommended to consult a doctor in time, after a clear diagnosis and follow the doctor’s instructions for treatment.