In the process of infertility, especially in the process of assisted technology for pregnancy, ovulation-promoting drugs are often used, and when the follicles are mature, HCG is then applied to promote the elimination of eggs. This series of symptoms caused by large HCG is called ovarian hyperstimulation syndrome. This phenomenon is usually seen in patients with polycystic ovary syndrome and in drug-sensitive individuals, who sometimes have dozens of follicles developing at the same time once the drug is administered. How to manage ovarian hyperstimulation syndrome? The severity of the clinical manifestations of ovarian hyperstimulation syndrome is divided into three degrees: mild, moderate and severe. Mild ovarian hyperstimulation syndrome: manifested by weight gain, thirst, abdominal discomfort, slight swelling of the lower abdomen, mild malignancy and vomiting. Ultrasound indicates enlarged ovaries (>5 cm in diameter) with multiple corpus luteum and a small amount of fluid in the abdominal cavity. Moderate ovarian hyperstimulation syndrome: malignant vomiting, increased abdominal distension, abdominal pain, shortness of breath, but no significant fluid loss and electrolyte balance imbalance on laboratory results. Physical examination reveals an enlarged abdomen without abdominal muscle tension, the ascites sign may be positive, and significant ovaries may be visualized. Ultrasound shows cystic ovarian enlargement (>7 cm) and a moderate amount of peritoneal fluid. Severe ovarian hyperstimulation syndrome: symptoms are further aggravated with clinical signs of massive fluid loss (e.g. irritability, rapid pulse, low blood pressure). A few sentences of fluid in the third interval, the appearance of peritoneal fluid or even intestinal fluid, hypovolemic shock, hemoconcentration, low urine and disturbed water-electrolyte balance, etc. Physical examination shows abdominal tension, positive ascites sign and significantly enlarged ovaries. Ultrasonography shows ovarian diameter >10 cm. In very severe cases, acute respiratory distress syndrome may occur due to massive ascites, pleural fluid and pericardial effusion, and may also be complicated by complications such as liver and kidney failure and thrombosis. In some patients, ovarian torsion, rupture and bleeding of flavin cysts may even occur due to the huge ovaries and other acute abdominal conditions. What should we do if ovarian hyperstimulation syndrome occurs? Generally speaking, if it is mild or moderate patients do not need hospitalization, but they must avoid strenuous exercise or exertion to avoid ovarian torsion, drink high protein water, drink sports drinks appropriately (not less than 1500ml per day is recommended), and visit the hospital regularly for blood sampling to test serum electrolytes, hematocrit and coagulation, and ultrasound to assess ascites. Timely detection and timely management of ovarian solitary stimulation syndrome is very important, otherwise it can have adverse consequences. For the patient, what needs to be highlighted to the physician at each hospital visit? The answer is: you need to state to the doctor how much fluid you drink each day, how much urine you have, the change in weight each day, and any changes in symptoms that you think are important. If you have symptoms such as inability to lie down, difficulty breathing, vomiting, diarrhea, dizziness, etc., you need to go to the hospital promptly to avoid serious complications. Severe patients will need to be hospitalized and closely monitored for changes in their condition.