For the first time chemotherapy for lung cancer patients, the specific days of reaction need to be analyzed according to the chemotherapeutic drugs used and individual differences in medication. 1. Different chemotherapeutic drugs: the reaction time of different chemotherapeutic drugs will have some differences. If patients use cisplatin and other chemotherapy drugs that are easy to cause vomiting, they may show severe nausea, vomiting and loss of appetite on the same day of chemotherapy; if patients use drugs that can affect cardiac function, such as adriamycin or docetaxel, it will take about ten days after the use of the drug to have the related reaction symptoms; and the symptoms of alopecia areata will generally be manifested in about ten to twenty days after the chemotherapy. 2. Individual differences: the length of the reaction time needs to be judged according to individual differences, and there is a clear relationship with the strength of the patient’s physical and nutritional status. If the patient is malnourished and in poor physical condition, the effect of chemotherapy is poor, the reaction of chemotherapy is large, and the body is not easy to tolerate, and the time of reaction is faster. Therefore, patients should increase their nutritional intake before chemotherapy to enhance their physical fitness, and pay attention to dietary regulation during chemotherapy to alleviate the chemotherapeutic reactions brought about by chemotherapeutic drugs. If the reaction is large and the body does not tolerate it, appropriate symptomatic treatment should be carried out or the chemotherapy program should be changed or even stopped.