The occurrence of morning sickness is most often caused by digestive disorders such as reflux gastroenteritis, gastric ulcers, and duodenal ulcers. Especially in the morning on an empty stomach, the symptoms of reflux gastritis and gastric ulcers are more obvious and may cause morning sickness. In addition to digestive disorders, chronic pharyngitis may also cause morning sickness, and the morning is the main attack time for chronic pharyngitis. If there is chronic inflammation in the nose, it may also lead to backflow of secretions and trigger nausea. If you are a woman of childbearing age, you should also be aware of the possibility of pregnancy. If you experience morning sickness on a regular basis, you must go to the hospital for prompt examination. Both digestive system diseases and nausea caused by chronic pharyngitis and rhinitis should be treated promptly to avoid aggravation of the condition.