Lung cancer immunotherapy side effects are reflected in multi-systems and multi-symptoms, mainly in gastrointestinal reactions, hepatotoxicity, endocrine damage and so on. The main mechanism is to cause excessive activation of immune cells in the organism. 1. Gastrointestinal reaction: including abdominal distension, abdominal pain, vomiting, anorexia, etc. 2. Hepatotoxicity: yellowing of the skin or mucous membranes, loss of appetite and other symptoms of hepatitis can occur. 3. Endocrine-related damage: such as thyroid, pituitary gland, adrenal glands, etc., mainly manifested as fatigue, weight gain or loss, dizziness or fainting, constipation, etc. 4. Other adverse reactions: more serious immune-related myocarditis, pneumonia, nephropathy and so on. The overall incidence of side effects of immunotherapy for lung cancer is relatively low compared with traditional radiotherapy and chemotherapy. If this kind of reaction occurs when using immunotherapy, treatment should be given early to avoid serious adverse events. Drugs need to be used under the guidance of doctors and avoid self-medication.