Chemotherapy, also known as “chemotherapy”, is one of the treatments for tumors. While it saves human lives, it also brings a lot of toxic side effects, so it can be said that chemotherapy is a kind of intimidating treatment method. According to relevant data, more than 75% of tumor chemotherapy patients will produce different degrees of nausea, vomiting reaction, some people even choose to give up chemotherapy. Why does chemotherapy have so many adverse reactions and what is its therapeutic significance? What is chemotherapy? Chemotherapy is simply to fight poison with poison, and chemotherapy is the only treatment option for some tumors. Tumor chemotherapy is the application of chemical drugs (including endocrine drugs) to treat malignant tumors. Anti-cancer drugs are quickly distributed to the whole body after entering the body, which can kill both local tumors and distant metastatic tumors, so chemotherapy is a kind of systemic treatment. The effect of chemotherapy depends on the type and condition of the tumor, some of them can be cured, and more of them can inhibit the growth and spread of the tumor. There are more than 50 chemotherapeutic agents, most of which are chemically synthesized and cytotoxic. Chemotherapy is one of the important means of treating malignant tumors. Together with surgery and radiotherapy, it is one of the three major treatments. Surgical resection is the preferred treatment for most tumors, and for some limited tumors with little tendency to spread (such as skin cancer), surgery or radiotherapy alone can cure them. However, for tumors with obvious tendency to spread (e.g. small cell lung cancer, testicular tumor, osteosarcoma, lung adenocarcinoma, etc.), even if surgery or radiotherapy alone can not prevent tumor recurrence and distant metastasis at the early stage, some patients can not obtain radical efficacy even though radical surgery or extended radical surgery is used and systemic chemotherapy is needed. Since chemotherapy is a systemic treatment, it is the main treatment for some tumors with systemic dissemination tendency and middle and late stage tumors. Difference between chemotherapy and surgery What is the difference between chemotherapy and surgery? This is one of the biggest questions in patients’ mind. The significance of surgery is to remove the tumor and relieve the tumor. However, surgery cannot do anything about the tiny metastases outside the lesion. After surgery, the tumor is relieved of its burden, but the tiny foci continue to grow rapidly and may even proliferate faster. Chemotherapy can help to reduce recurrence and metastasis, and “nip in the bud” the micrometastasis of the tumor as much as possible, or limit the micrometastasis to a locally controllable range. Chemotherapy is most effective within one week after surgery. When chemotherapy drugs enter the bloodstream and travel through the body to reach most tissues. The drugs kill specific cells, especially rapidly proliferating cells. This means that tumor cells are more affected by chemotherapy drugs, but some normal cells in the body are also damaged to varying degrees. Why chemotherapy causes nausea, vomiting and hair loss Chemotherapy drugs are not specifically targeted; they only act to inhibit cells that are growing fast. Tumor cells grow particularly fast, are particularly vigorous cells, chemotherapy drugs into the body will kill it. There are also some normal cells in the human body that grow very fast, and chemotherapeutic drugs will also work on them: 1. Hair: Hair grows every day. So after chemotherapy drugs enter the body, all the fast-growing cells are inhibited, including both abnormal tumor cells and some normal growth cells, which will cause hair loss. 2, intestinal mucosa: intestinal mucosa is renewed every day, but also relatively fast-growing cells, so chemotherapy drugs into the body will also damage these cells, causing nausea and vomiting. Overall, what parts of the body grow faster, chemotherapy drugs will have an impact on this part.