The causes of constant nausea and regurgitation include early pregnancy reaction, gastroesophageal reflux disease and gastroenteritis. 1. Early pregnancy reaction: If the patient is a woman and has a history of sexual intercourse, consider that she may be pregnant. When the patient is pregnant, the secretion level of estrogen and progesterone in the body will increase, triggering a series of reactions such as nausea, vomiting, acid reflux, fatigue, drowsiness and so on. 2. Gastroesophageal Reflux Disease (GERD): When the gastric acid secretion in the patient’s stomach is too much and the sphincter of the lower esophagus is relaxed, it will cause the gastric acid to reflux into the esophagus and stimulate the mucous membrane of the esophagus wall, which will trigger the patient to experience gastrointestinal discomfort such as nausea, regurgitation, vomiting and other symptoms. 3. Gastroenteritis: Inflammatory infection occurs in the gastrointestinal tract due to unclean diet, cold abdomen, etc. When the inflammatory factor constantly stimulates the mucous membrane of the gastrointestinal tract, it will trigger the patient to experience diarrhea, nausea, vomiting, regurgitation and other symptoms. If the patient frequently appear nausea, regurgitation and other symptoms, it is recommended that the patient go to the hospital in a timely manner, perfect ultrasound, gastroscopy and other tests, to clarify the cause of the disease, and comply with the doctor’s instructions for treatment, so as not to cause adverse consequences.