Chemotherapy is different from surgery and radiotherapy in that it is a systemic treatment that focuses on the whole body, and it is administered orally and intravenously to kill residual cancer cells throughout the body. Cancer is the local manifestation of a systemic disease. Chemotherapy plays an important role in eliminating distant metastasis and preventing recurrence of breast cancer, and is an indispensable and important part of breast cancer treatment. However, chemotherapeutic drugs can kill cells in an indistinct manner, killing tumor cells as well as normal cells in the body. Therefore, chemotherapy may cause the following toxic effects and adverse reactions: 1. Inhibition of bone marrow hematopoietic system. It mainly causes the decrease of white blood cells and platelets. Before each chemotherapy, if the white blood cells <3.5×109/L, platelets <50×109/L and hemoglobin <60g/L, chemotherapy should be temporarily stopped and drugs to raise blood cells should be used according to the doctor's prescription. In addition to the original treatment with shark liver alcohol, lispro, nucleotides and vitamin B6, as well as Chinese herbal medicine to benefit the blood, some colony-stimulating factors produced by recombinant genetic engineering in recent years have obvious functions to promote blood cell proliferation. Only when these drugs are used at the right time after chemotherapy, myelosuppression can be controlled. 2.It can damage the liver cells to different degrees. There can be increased glutamate transaminase, rising bilirubin, hepatomegaly, pain in the liver area, jaundice, etc. In severe cases, it can cause cirrhosis and disorders of blood clotting mechanism. Before each chemotherapy, you should cooperate with the doctor in charge and draw fasting blood to check liver function, so that problems can be found and solved in time and chemotherapy can be stopped if necessary. 3.Toxic effects on cardiovascular system. Heart failure can occur in very few patients. Therefore, you should cooperate with the doctor for electrocardiogram examination before using the drug, and stop the drug immediately if abnormalities are found, and treat them in time. Patients with previous history of heart disease should take the initiative to inform the doctor in charge and avoid using chemotherapeutic drugs with toxic effects on the heart in chemotherapy. 4. Toxic effects and adverse reactions of the urinary system are manifested by proteinuria, oliguria or anuria, and in some cases, hematuria. In order to be able to clearly understand the kidney function, before and during the use of drugs should be regularly checked, find the problem, timely treatment. In the treatment in to drink more green tea water and take diuretic and laxative herbs, so that the daily urine volume in 2000 to 3000 ml. Experience has shown that this can reduce the toxic effects of the urinary system and adverse reactions; 5. Certain drugs can affect fertility and lead to malformations. During chemotherapy, male patients should be sterilized, female patients should be discontinued or avoided if there is a pregnancy chemotherapy general fertility function can be restored after discontinuation of drugs; 6, hair loss and skin reactions do not occur in all patients, and even if they occur, there is no need to worry too much, because the general patient will grow back after discontinuation of drugs, hair loss, skin erythema, rash and hyperpigmentation will also improve or disappear; 7, in the systemic reactions of chemotherapy The toxic effects and adverse reactions of the digestive system are the most troublesome for patients, such as nausea, vomiting, loss of appetite, abdominal pain, diarrhea, as well as oral mucosal ulcers and pharyngitis. Damage to the digestive tract includes damage to the mucosal epithelium of the stomach, intestines, mouth, and pharynx, manifesting as varying degrees of nausea, vomiting, loss of appetite, abdominal pain, diarrhea, constipation, oral ulcers, and difficulty swallowing.