Excessive secretion of progesterone in pregnant women can lead to the appearance of nausea and acid reflux. Progesterone mainly acts on the lower end of the esophagus, which is close to the stomach, and often causes relaxation of the esophageal sphincter, thus causing reflux of gastric juices. Therefore, early pregnancy in pregnant women is often accompanied by nausea and vomiting. The vomit of pregnant women is mainly stomach contents or liquid mainly gastric juice, of which stomach acid is a component, so pregnant women often think that stomach acid increases after pregnancy, but in fact the total amount of stomach acid does not increase. If the nausea and acid reflux are more serious in early pregnancy, it is recommended to seek medical treatment in time.