About half of women will experience early pregnancy reactions in early pregnancy, including dizziness, fatigue, drowsiness, loss of appetite, partial eating, aversion to greasy food, nausea and vomiting. The severity and duration of symptoms vary from person to person, most of them appear around 6 weeks of pregnancy, reach the peak in 8-10 weeks, and disappear on their own around 12 weeks of pregnancy. A small number of pregnant women have severe early pregnancy reaction, frequent nausea and vomiting, unable to eat, resulting in fluid imbalance and metabolic disorders, and even endangering the life of pregnant women. The cause of early pregnancy reaction may be related to the increase of human chorionic gonadotropin (HCG) in the body, gastrointestinal dysfunction, reduction of gastric acid secretion and prolonged gastric emptying time. 0.3% to 1% of pregnant women will experience severe pregnancy vomiting, mostly in young primigravida, which is generally believed to be related to the significant increase of HCG. This is based on the fact that the time of appearance and disappearance of the early pregnancy response coincides with the time of rise and fall of the maternal blood HCG value. The significantly higher blood HCG values and the high incidence of severe vomiting in pregnant women with gravid and multiple pregnancies suggest that severe pregnancy vomiting may be associated with elevated HCG levels. However, the degree of clinical manifestations is sometimes not necessarily proportional to the blood HCG level. Pregnant women with excessive mental stress, anxiety, worry and poor living environment and economic status are prone to severe pregnancy vomiting, suggesting that the disease may be related to mental and social factors. Recent studies have found that hyperemesis gravidarum may also be associated with Helicobacter pylori infection. Symptoms: Hyperemesis gravidarum occurs between early pregnancy and 16 weeks of gestation, mostly in young first-time pregnant women. Early pregnancy reactions usually appear around 40 days after menopause and gradually worsen until frequent vomiting and inability to eat. Bile or coffee-like substances are present in the vomitus. Severe vomiting can cause water loss and electrolyte disturbance, and use the body fat, so that its intermediate product acetone accumulation, causing metabolic acidosis. Patients experience significant weight loss, pallor, dry skin, weak pulse, decreased urine output, and in severe cases, decreased blood pressure, causing pre-renal acute renal failure. Vitamin B1 deficiency can lead to Wernicke’s syndrome, with clinical manifestations of central nervous system symptoms, namely nystagmus, visual impairment, ataxia, increased speech in the acute phase, followed by gradual mental retardation, drowsiness, and individual occurrence of xylophobia or coma. If not treated in time, the mortality rate reaches 50%. Vitamin K deficiency can lead to coagulation dysfunction, often accompanied by a decrease in plasma protein and fibrinogen, and an increased tendency of bleeding in pregnant women, which can lead to rhinorrhea and even retinal hemorrhage. Differentiation: Hyperemesis gravidarum, hyperthyroidism and diseases that may cause vomiting, such as hepatitis, gastroenteritis, pancreatitis, biliary tract diseases, etc. should be differentiated. Those with neurological symptoms should be differentiated from meningitis and brain tumors. Treatment: Mild nausea and vomiting is a common symptom in early pregnancy, which can be relieved by eating a small number of meals and taking vitamin B6. Patients with severe pregnancy vomiting should be hospitalized, fasted for 2 to 3 days, and hydrated and electrolyte supplemented as appropriate according to laboratory results to clarify the water loss and electrolyte disorders. Daily intravenous drip of glucose solution and Ringer’s solution with vitamin B6, vitamin C, potassium chloride, etc. Maintain the daily urine volume above 1000 ml. And give vitamin B1 intramuscularly. For malnutrition, fatty milk and amino acids can be given intravenously. Generally after 2-3 days of the above treatment, the condition can be improved. Pregnant women can try a small amount of liquid diet after vomiting stops and symptoms are relieved, and if there is no adverse reaction, the amount of food can be gradually increased, while adjusting the amount of rehydration. Most of the pregnant women with severe pregnancy vomiting can continue their pregnancy after treatment. If conventional treatment is ineffective, termination of pregnancy should be considered if there is persistent jaundice, persistent proteinuria, elevated body temperature, persistent above 38°C, tachycardia (≥120 beats/min), and Wernicke syndrome, which endangers the life of the pregnant woman.