Morning stomach discomfort may be caused by autonomic dysfunction, functional dyspepsia, gastroesophageal reflux and other diseases. 1. Autonomic dysfunction: The occurrence of this disease is often related to psychosocial stress factors, such as long-term mental stress, stressful events stimulation, etc., and in some cases, it is also related to genetics, nutritional and metabolic disorders and other factors. Stomach discomfort is a typical symptom, which can be manifested as stomach pain, stomach bloating and so on. 2. Functional dyspepsia: The causes of this disease include heredity, excessive secretion of gastric acid, increased sensitivity of internal organs, and poor eating habits. If the patient consumes too much food before going to bed the night before, which affects the digestive function of the gastrointestinal tract, he/she is prone to feel uncomfortable in the stomach when waking up in the morning. 3. Gastroesophageal reflux: This disease is related to the reduced resistance and clearance of the esophageal mucosa as well as the impaired function of anti-reflux structures. Typical symptoms include bloating, stomach pain, belching (burping), etc. Some patients may feel sick in the morning, and may also experience reflux, heartburn and other symptoms. Morning sickness may also be a sign of early pregnancy, etc. It is recommended that patients who often feel sick in the morning go to the hospital for a complete examination to clarify the cause of the problem.