Toxic side effects of chemotherapy. Immediate toxicity and long-term toxicity: Immediate toxicity is divided into local reactions (such as local tissue necrosis, embolic phlebitis, etc.) and systemic reactions (including the digestive tract, hematopoietic system, cardiac reactions, pulmonary toxicity, renal dysfunction and other reactions, etc.). Long-term toxic reactions are mainly reproductive dysfunction and carcinogenic and teratogenic effects. In addition, chemotherapy can sometimes have complications due to its toxic side effects, commonly including infection, bleeding, perforation, uric acid crystals and so on. Common toxic side effects are as follows: 1, local reactions: phlebitis, local tissue necrosis. 2, myelosuppression: most chemotherapeutic drugs have different degrees of myelosuppression. Myelosuppression can be manifested in the early stage of leukocyte, especially granulocyte reduction, and in severe cases, platelets, red blood cells, hemoglobin can be reduced, and patients can also have fatigue, resistance to decline, easy to infection, fever, bleeding and other manifestations. 3, gastrointestinal toxicity: most chemotherapeutic drugs can cause gastrointestinal reactions, manifested as dry mouth, loss of appetite, nausea, vomiting, and sometimes oral mucositis or ulcers. Constipation, paralytic bowel obstruction, diarrhea, gastrointestinal bleeding and abdominal pain can also be seen. 4. Immunosuppression: chemotherapeutic drugs are generally immunosuppressive drugs, which have different degrees of inhibition on the immune function of the body. When the immune function is low, the tumor is not easy to be controlled, but speeds up the process of recurrence or metastasis. 5, Nephrotoxicity: some chemotherapeutic drugs can cause kidney injury, mainly manifested as acute necrosis of renal tubular epithelial cells, degeneration, interstitial edema, tubular dilatation, and renal failure in severe cases. Patients may have low back pain, hematuria, edema, urine test abnormalities. 6, liver injury: chemotherapeutic drug-induced liver reaction can be acute and transient liver damage, including necrosis, inflammation, or due to long-term use of drugs, causing chronic liver injury, such as fibrosis, steatosis, granuloma formation, eosinophil infiltration and so on. Clinical manifestations can be abnormal liver function, liver pain, hepatomegaly, jaundice and so on. 7, cardiotoxicity: clinical manifestations can be arrhythmia, heart failure, cardiomyopathy syndrome (patients show weakness, active dyspnea, episodic nocturnal dyspnea, rapid pulse, rapid respiration, hepatomegaly, cardiomegaly, pulmonary edema, edema and pleural fluid, etc.), and ECG abnormalities. 8, pulmonary toxicity: a small number of chemotherapy can appear pulmonary toxicity, manifested as interstitial inflammation and pulmonary fibrosis. Clinical manifestations may be fever, dry cough, shortness of breath, most patients with acute onset, accompanied by agranulocytosis. 9, neurotoxicity: some chemotherapeutic drugs can cause peripheral neuritis, manifested as numbness of the fingers (toes), tendon reflexes, sensory abnormalities, and sometimes constipation or paralytic intestinal obstruction can also occur. Some drugs can produce central neurotoxicity, mainly manifested as sensory abnormalities, vibration sense weakening, limb numbness, tingling, gait disorders, ataxia, drowsiness, mental anomalies and so on. 10, hair loss: some chemotherapy drugs damage hair follicles, the degree of hair loss is usually related to the concentration and dose of drugs. 11, other: such as hearing loss, rash, facial or skin flushing, nail deformation, osteoporosis, bladder and urethral irritation, infertility, amenorrhea, sexual dysfunction, male breast enlargement can also be caused by some chemotherapeutic drugs.