Fluid buildup at the base of the thigh is considered to be a disease of the hip joint. For example, hip synovitis, hip tuberculosis, and septic arthritis of the hip joint. You can go to the orthopedic department in time to find a doctor’s interview, the doctor combined with the examination for preliminary analysis. You can improve the X-ray of the hip joint to determine whether there is any obvious abnormality of the bone, and improve the magnetic resonance examination to understand the degree of fluid accumulation and the possible causes. If it is synovitis of the hip joint, it is necessary to pay attention to rest and avoid strenuous exercise, which will help natural relief. If it is tuberculosis of the hip joint, it is necessary to apply isoniazid and rifampicin for anti-tuberculosis treatment. If it is septic hip arthritis, antibiotic treatment such as cephalosporin and surgical placement of tubes for irrigation and drainage, if necessary, will help recovery.