For gastric cancer nausea and vomiting, first of all, the causes of nausea and vomiting should be clarified: First, if it is gastric cancer of gastric sinus, the possibility of pyloric obstruction is considered to be high, so it is recommended that the patient undergoes a systemic examination, and if surgery is possible, surgical treatment is preferred, and if the opportunity of surgical treatment is lost, it is recommended that gastrointestinal decompression, intravenous rehydration, and intravenous chemotherapy control the tumor, so as to release the pyloric obstruction as much as possible. Second, nausea and vomiting of lung cancer may be caused by abdominal metastasis, leptomeningeal metastasis, liver metastasis, etc. At this time, it is necessary to carry out intravenous chemotherapy and targeted therapy to control the tumor; third, nausea and vomiting of stomach cancer do not exclude external ionic disorders, such as hyponatremia and hypochloremia, so at this time, it is necessary to check the ionic status of blood and correct the ionic disorders in a timely manner.