There are many causes of stomach upset and nausea. Common causes are: 1, women of childbearing age with symptoms of stomach discomfort and nausea are considered to be pregnancy reactions caused by pregnancy, accompanied by weakness, drowsiness and lethargy, it is recommended to do urine pregnancy test examination, uterine ultrasound examination. 2, stomach discomfort, nausea and vomiting caused by improper diet or abdominal cold caused by gastrointestinal dysfunction, indigestion, it is recommended to eat regularly, avoid overeating and pay attention to 3, certain digestive system diseases, such as pancreatitis, cholecystitis, gastric ulcer, chronic gastritis, can appear nausea, vomiting symptoms, to go to the hospital for abdominal ultrasound, gastroscopy, to clarify the cause. 4, neurological diseases, such as hypertension, brain hemorrhage patients, can also appear stomach discomfort, nausea, vomiting.