Pain at the root of the thigh, if there is no trauma, is commonly caused by femoral head necrosis of the hip joint or synovitis of the hip joint or dysplasia of the hip joint. There are also tumors of the hip joint, including tumors of the upper femur, whether benign or malignant, which may cause pain at the root of the thigh. Lumbar disc herniation pain radiating to the root of the thigh may also cause pain at the root of the thigh. Another autoimmune disease, such as rheumatoid arthritis, ankylosing spondylitis, and even gout, can also cause pain or swelling in the hip joint at the base of the thigh. Infections of the hip joint, including bacterial or tuberculosis infections, can also cause pain and swelling at the base of the thigh. Therefore, if the pain at the root of the thigh is not relieved within a short period of time, you must go to a regular hospital for a clear diagnosis and choose a scientific and reasonable treatment method.