Generally speaking, as long as chemotherapy drugs are used, there will be different degrees of damage to normal cells, but the damage of chemotherapy to the human body depends on the individual’s physical condition, drug dose, and tolerance ability. If the individual is in good health, the tolerance ability is higher and the damage of chemotherapy is not particularly great. If the individual’s health is poor, the tolerance ability is also poor, and the damage caused by chemotherapy is relatively large. Therefore, the use of chemotherapy drugs needs to be prescribed by doctors with rich experience, and the application of anti-tumor drugs should take into account the adverse reactions of patients and avoid damage to normal tissues as much as possible. The damage to human body can be divided into digestive system, cardiovascular system, nervous system, skin system, immune system, bone marrow suppression and urinary system: 1. Digestive system: the damage to digestive system is the most common and can be seen as gastrointestinal reactions, such as nausea, vomiting, loss of appetite, diarrhea, etc. Some patients may be constipated and have intestinal paralysis. 2. Acute cardiomyopathy can be seen as abnormal electrocardiogram, which will recover on its own after stopping the drug, while chronic cardiomyopathy is more serious and can occur as palpitations, arrhythmia, chest tightness and other uncomfortable symptoms, or even cardiac arrest and other dangers; 3. Neurological system: can be manifested as chronic progressive hemiplegia, numbness of extremities, impaired limb movement, drowsiness, unsteadiness and other mental manifestations; 4. Skin system. May appear symptoms of large hair loss, such as hair, eyebrows, etc., while the stimulation of chemotherapy drugs may lead to the occurrence of phlebitis, if the drug extravasation, it will cause local tissue necrosis; 5, immune system: may appear local rash itching, also can occur chest tightness, panic attacks and other manifestations, serious cases will appear anaphylaxis; 6, bone marrow suppression: may have a decrease in the number of white blood cells, red blood cells, platelets, patients appear fever, mucosal bleeding and other symptoms, or lead to anemia; 7. Urinary system: it may cause damage to kidney function, cause inflammation of the bladder, and examination may reveal a decrease in creatinine clearance. In addition to the above systems, chemotherapy can also cause pulmonary fibrosis, which needs to be used with caution in patients with poor lung function; as chemotherapy drugs are mostly administered intravenously, they can stimulate the blood vessel walls and cause phlebitis, which needs to be prevented. In addition, liver damage, reduced fertility, and slow growth can occur. Most of the damage caused by chemotherapy will gradually subside when the drugs are stopped, but some of the damage may cause permanent damage to organs and even cause diseases such as lymphoma and leukemia. Therefore, chemotherapy drugs should be used under the guidance of a doctor, with regular follow-ups after chemotherapy, to ensure the intake of nutrients and to maintain a good and optimistic state of mind.