The following diseases should be alerted for pain at the root of the thigh when walking: First, be alert for the presence of hip synovitis, which can lead to pain at the root of the thigh when walking and may be accompanied by joint effusion and hip joint swelling. Secondly, if you have a history of long-term alcohol consumption, trauma or hormone use, you must be alert to the presence of ischemic changes in the femoral head, or even possible ischemic necrosis of the femoral head. Therefore, if you experience frequent pain at the root of the thigh when walking, you should have a femoral head examination to rule out this disease. Finally, be alert to the presence of infectious diseases of the hip joint, such as tuberculosis of the hip joint and bacterial infection of the hip joint. Of course, it is also necessary to exclude relatively rare diseases such as hip osteoarthritis, hip rheumatoid arthritis and ankylosing spondylitis.