The patient, a 68-year-old female, developed a large amount of pericardial effusion, pleural effusion, abdominal effusion, and pelvic effusion more than 4 months ago after a fever of unknown origin. She visited major hospitals several times and was even hospitalized for thoracoscopy, taking pericardial biopsy, pleural biopsy and peritoneal biopsy, ruling out the possibility of various rheumatic diseases and undergoing systematic anti-TB treatment for one month, but it was still difficult to clarify the cause, with some doctors saying that tumors were not excluded and others saying that anti-TB time was still not enough to exclude tuberculosis. For 4 months, the patient’s symptoms not only did not improve, but also worsened. The patient and his family were almost desperate. The patient’s son came to our Infectious Diseases Department with the idea of coming to Beijing for a trial. After learning about the patient’s diagnosis and treatment, all the medical and nursing staff of the Department of Infectious Diseases attached great importance to it. In close cooperation with all the auxiliary departments, we ruled out tumor, tuberculosis, immune diseases and infectious diseases in just one week, and finally diagnosed the patient as having hypothyroidism caused by viral infection, which led to multiple plasma cavities. The entire consultation and treatment cost just over 6,000 RMB.