The vague pain above the root of the left thigh may be caused by several reasons: 1. hip arthritis, aseptic inflammation of the hip joint, which usually appears suddenly. It can take oral non-steroidal anti-inflammatory drugs or rest for a period of time, and will slowly improve. 2, may be aseptic ischemic necrosis of the femoral head, commonly seen in patients who smoke and drink for a long time, or people who apply glucocorticoids for a long time. Early symptoms are similar to those of hip osteoarthritis, with local vague pain or increased pain when bearing weight and walking. If the head of the femur collapses in the middle and late stages, the lower limb will be shortened and deformed. 3, may be local lymph nodes swelling caused by pain, common in the lower limb soft tissue infection, such as calf dermatitis or foot tinea pedis, and nail infection caused by infection, through the lymphatic vessels spread to the inguinal lymph nodes caused by swelling, pain.