The main reasons for elevated blood glucose after chemotherapy for lung cancer are that the drugs used in chemotherapy (e.g., glucocorticoids) can elevate blood glucose, and the toxicity of chemotherapeutic agents (e.g., platinum and methotrexate) may also cause abnormal blood glucose. Glucocorticoids used in chemotherapy promote gluconeogenesis, which can make blood sugar rise. Liver and kidney damage caused by chemotherapeutic agents can indirectly interfere with glucose metabolism, resulting in abnormally elevated blood glucose. In addition, the direct and indirect cytotoxicity of chemotherapeutic drugs (platinum, methotrexate, peptidase, cyclophosphamide, etc.) on pancreatic islet B-cells can inhibit insulin synthesis and secretion, thus leading to elevated blood glucose. When blood glucose rises abnormally, it is necessary to go to a regular hospital for medical treatment.