Many patients are fearful of chemotherapy. In fact, chemotherapy is not scary, and there are measures to prevent and treat adverse reactions to chemotherapy, which can protect patients to pass through the chemotherapy period safely and smoothly. The following is a brief description of the common adverse reactions and treatment methods for your understanding. 1, gastrointestinal reactions (1) nausea and vomiting, loss of appetite: cisplatin and anthracyclines are heavier, mainly because the drug causes the release of 5-hydroxytryptamine (5-HT) and other substances, acting on the cerebral cortex, the fourth ventricular chemoreceptor area and activating the medulla oblongata vomiting center to cause vomiting. At present, all patients are routinely treated with antiemetic prophylaxis during chemotherapy, and individual patients with severe reactions need to use a combination of antiemetic drugs with different mechanisms. (2) Diarrhea and constipation: Some drugs such as paclitaxel and vincristine have a certain proportion of intestinal symptoms, and if diarrhea or constipation occurs, most of them are mild and can be improved by giving symptomatic supportive treatment. (3) Oral mucositis: rapidly proliferating mucosal tissue is easily damaged by chemotherapeutic drugs, manifesting as oral mucosal pain and some ulcers, commonly seen with methotrexate and fluorouracil drugs. Patients with oral mucositis can apply mouthwash (to prevent bacterial and fungal infections), gargle with lidocaine solution before eating to relieve pain, give vitamin B2 and other multivitamins, and give intravenous nutritional support therapy if necessary. Bone marrow suppression Bone marrow suppression is a common adverse effect of chemotherapy, manifested as a decline in white blood cells, red blood cells and platelets. (1) Decline in white blood cells and granulocytes: the most common. The half-life of granulocytes is the shortest, about 6~8 hours, so they are the first to decline, and the lowest value usually occurs 7~13 days after chemotherapy. The treatment of leukocyte and granulocyte decline is effective, with granulocyte colony-stimulating factor as the mainstay, and protective isolation, room disinfection and prophylactic application of antimicrobial agents are also required for decreases below grade IV. The application of these measures can safely protect patients through the post-chemotherapy myelosuppression period. (2) Red blood cells and hemoglobin decline: can occur after multiple cycles of chemotherapy, generally a mild decline, if necessary, the application of erythropoietin or infusion of red blood cell suspension to ensure the smooth progress of treatment. (3) Platelet decline is rare: individual drugs have the adverse effect of platelet decline, mild decline does not require treatment, in more severe cases, platelet colony-stimulating factor, platelet transfusion and other measures can be used, and patients with platelet reduction below degree IV need appropriate braking. 3, hepatotoxicity Clinical manifestations are elevated serum glutathione and glutamic oxalacetic transaminase or elevated serum bilirubin. Liver-protective drugs can be used routinely or therapeutically during chemotherapy, and in severe cases, chemotherapy needs to be discontinued. 4.Nephrotoxicity Clinical manifestations: Mild damage can be clinically asymptomatic with elevated creatinine, mild proteinuria and microscopic hematuria; severe renal failure can occur. Nephrotoxicity is mainly preventive. The majority of chemotherapeutic drugs have insignificant nephrotoxicity, with cisplatin and methotrexate being relatively common. Therefore, cisplatin is routinely hydrated and diuretic when applied and 24-hour urine volume is counted to reduce the effect of drugs on the kidney. 5, neurotoxicity paclitaxel and vincristine are mostly seen as peripheral neuropathy, manifested as numbness and pain in the extremities (common in fingers and toes), cisplatin is seen as auditory nerve changes, manifested as tinnitus and hearing loss, etc. Most of them are not serious and can continue treatment, and most of them can recover on their own when they are not tolerated. Application of nutritional drugs can reduce the symptoms. 6, skin toxicity clinical manifestations of hair loss (usually reversible), skin pigmentation, rash and hand-foot syndrome (Hyloda, 5-FU), such reactions affect the aesthetic, most reversible, gradually recovered after discontinuation of the drug. 7, allergic reactions A few drugs can cause rapid-onset allergic reactions, so pretreatment is routinely given, such as doxorubicin and paclitaxel before and after treatment with routine preventive application of hormones to prevent the occurrence of allergic reactions. There are also some rare adverse reactions, such as pulmonary toxicity, cardiotoxicity, etc. Routine examination of blood routine, urine routine, liver and kidney function, blood sugar and electrocardiogram before chemotherapy, and routine application of prophylactic and protective drugs during chemotherapy are all necessary measures to ensure that chemotherapy is carried out safely, so good cooperation between family members and patients is a prerequisite to ensure regular treatment. Chemotherapy is not terrible, I wish all patients to build confidence and strive for early recovery!