Immunotherapy is generally used in the late stage of stomach cancer, and its principle is to increase the patient’s own immunity by hitting some drugs, and through these immune cells to recognize the abnormal cancer cells, kill the cancer cells, and prolong the life’s effect. Since it increases one’s immunity, there is a possibility that it may have side effects on one’s own normal tissues as well, for example, autoimmune hepatitis, after hitting this drug, one will have abnormal liver function, yellow skin all over the body, and dyspepsia. Others may develop autoimmune pneumonia, which means they may have difficulty breathing, breathlessness, chest tightness, and decreased blood pressure and oxygen. Others can cause thyroiditis, that is, hyperthyroidism or hypothyroidism, abnormal levels of thyroid hormones in the body, this time the patient may be very excited or depressed. All these adverse reactions need to draw blood to check, but also combined with some of the patient’s own symptoms in time to go to the hospital to deal with.