The causes may be changes in hormone levels during pregnancy, gastrointestinal disorders, and emotional anxiety. In early pregnancy, changes in hormone levels such as increased secretion of progesterone and estrogen, elevated secretion of human chorionic gonadotropin, decreased secretion of gastric acid, emotional instability such as anxiety, and other factors can lead to nausea and vomiting, and unclean diets may lead to gastrointestinal disorders, prolonged digestion of food, and prolonged gastric emptying, leading to nausea and vomiting and other reactions in pregnant women. Pregnant women during early pregnancy should pay attention to the diet should be light and easy to digest, so as not to cause nausea and vomiting, and timely replenishment of water, to prevent the body from dehydration due to the reaction of pregnancy and vomiting.