Whenever chemotherapy is mentioned, many people first associate it with vomiting until bile is vomited, hair loss until none is left, mental depression, or decreased resistance, and they all have a sense of fear about the side effects of chemotherapy. In fact, if you can have a rough understanding of the causes of chemotherapy side effects and the principles of prevention and treatment, you may be able to face chemotherapy openly, minimize the side effects and get the maximum benefit from chemotherapy for cancer treatment. The so-called “chemotherapy” refers to the use of one or more chemical drugs to kill tumor cells and prolong the survival of patients. However, since there is no fundamental difference in metabolism between normal cells and tumor cells, while chemotherapy drugs kill tumor cells, they often have certain damage effects on normal cells, especially those tissue cells that are proliferating vigorously, like tumor cells, are most easily damaged by chemotherapy drugs. These proliferating tissue cells include gastrointestinal mucosa, hair follicle cells, leukocytes, etc. The damage to these cells causes the most common side effects during chemotherapy, such as nausea and vomiting, hair loss, and decrease in white blood cells. However, the cells of these normal tissues are more likely to recover from the damage of chemotherapy, making the damage of chemotherapy drugs to tumor cells more obvious for the purpose of tumor treatment. After understanding the causes of chemotherapy side effects, we also need to clarify several misconceptions in chemotherapy: Many people think that as long as chemotherapy is given, side effects such as vomiting and hair loss will inevitably occur. In fact, this view is wrong, not all chemotherapy patients will experience side effects. Each side effect occurs with some frequency, but not 100% of the time. The same drug may have one side effect in this patient and not in another, or another side effect. And the same side effect may be mild in some patients and may be more pronounced in others, also varying from person to person. Therefore, it is important not to refuse chemotherapy that you should receive because of side effects that others have experienced. Moreover, not all chemotherapy drugs have the same side effects. Some may have significant hair loss, some may have significant white blood cell drop, and some may not even have any side effects at all, and the side effects vary from drug to drug. When formulating chemotherapy regimens, in addition to considering the effectiveness of the treatment, doctors often individualize the choice of different chemotherapy regimens depending on the physical condition of different patients and their personal wishes regarding side effects. Therefore, if you are a patient, before receiving treatment, you should let your doctor fully understand your physical condition and tell him your level of acceptance of different side effects, as this will often make chemotherapy more acceptable to the patient and will help improve the effectiveness of chemotherapy. Many people believe that in order for chemotherapy to work, there must be side effects. This is also a misconception. In fact, there is no correlation between the side effects of chemotherapy and its efficacy. Effective chemotherapy regimens may sometimes have insignificant side effects, and chemotherapy that cures patients because of side effects is not a good treatment choice. The ideal chemotherapy regimen should be highly effective and less toxic, with the lowest side effects for the best outcome. With the development of medicine, more and more new drugs are being introduced, and these new drugs often have lower side effects and even better efficacy. Therefore, at present, during chemotherapy, the patient may not lose hair, or vomit, or the white blood cell does not decrease, but the efficacy is more significant, so the chemotherapy is more easily accepted by the patient. Moreover, the side effects of chemotherapy can be prevented or treated, and reasonable treatment methods can reduce the frequency of side effects, mitigate the degree of side effects, and shorten the duration of side effects. We will discuss the prevention and treatment of the most common side effects in chemotherapy. Nausea and vomiting are the most common side effects of chemotherapy and the most feared by patients. It usually occurs a few hours after chemotherapy, usually lasts 1-2 days, and occasionally lasts longer or makes it difficult for the patient to drip. However, the occurrence of nausea and vomiting can be reduced by changing the diet and using antiemetic medications appropriately. It is not advisable to eat too much during chemotherapy, eat less and more often, avoid indigestible and greasy food, cold and acidic food can reduce nausea, and distraction through chatting and watching TV can also alleviate gastrointestinal reactions. In addition, do not refuse to eat because of the fear of vomiting, often forced to eat a small amount of food can reduce nausea, reduce gastrointestinal damage. Hair loss is another common side effect that affects patients’ mood and is a common reason for patients to refuse chemotherapy. In fact, not all chemotherapy will cause hair loss, and the degree of hair loss varies from drug to drug and from patient to patient. Moreover, after chemotherapy is over, hair often grows back and even has better hair quality and color. In addition to the choice of drugs that can prevent hair loss, there are some measures in chemotherapy that can reduce the degree of hair loss. For example, using ice caps and mild shampoos, avoiding hard combs and hair coloring, and cutting hair short also make hair loss appear less obvious and easier to deal with. In addition, when hair loss is unavoidable, it is a wise choice to temporarily choose a suitable wig, which does not interfere with the chemotherapy carried out, but also does not affect the aesthetics, and allows you to change the hair style and color at will. Other side effects, such as diarrhea, constipation, and decreased white blood cells, are also managed by doctors and can be prevented by patients by changing their diet and lifestyle accordingly. Therefore, many side effects are not a direct reason for refusing chemotherapy. When patients can recognize these side effects and understand the preventive measures, we will find that chemotherapy is not as scary as it is said to be, and there is no need to be afraid of chemotherapy.