Chemotherapy is a kind of treatment that uses chemical drugs to kill tumor cells and inhibit the growth and reproduction of tumor cells. It is a systemic treatment that has therapeutic effects on primary foci, metastases and subclinical metastases, but chemotherapy treatment for tumors also kills normal cells and immune cells together with tumor cells, causing various discomforts to patients, i.e. chemotherapy side effects. The common side effects are as follows. 1.Weakness: Patients may suffer from fatigue and weakness, mental depression, sweating and drowsiness. 2, decreased immune function: chemotherapy drugs can damage the immune system of patients, resulting in defective or decreased immune function. Immune function indicators such as T-cell subsets and NK-cell activity may decrease in varying degrees after chemotherapy compared to before chemotherapy. Most antitumor chemotherapy drugs have immunosuppressive effects. 3. Myelosuppression: Most chemotherapy drugs can cause myelosuppression, which is manifested as a decrease in white blood cells and platelets, or even a decrease in red blood cells and hematocrit. Gastrointestinal reactions: decreased appetite, reduced diet, nausea, vomiting, abdominal distension, abdominal pain, diarrhea or constipation, etc. Most chemotherapeutic drugs stimulate the mucous membrane of the gastrointestinal tract to cause the above symptoms. 5.Inflammatory reaction: fever, dizziness, headache, dry mouth, mouth and tongue sores, etc. 6, cardiotoxicity: some chemotherapy drugs can produce cardiotoxicity, damage cardiomyocytes, patients appear panic, palpitations, chest tightness, anterior heart discomfort, shortness of breath and other symptoms, and even heart failure. The electrocardiogram may show T-wave changes or S-T segment changes, etc. 7, nephrotoxicity: some chemotherapeutic drugs in high doses can cause renal impairment, such as decreased creatinine clearance. 8, pulmonary fibrosis: cyclophosphamide, vincristine, bleomycin, etc. can cause pulmonary fibrosis, chest radiographs can be seen in the thickening of lung texture or striated changes, more dangerous for patients with poor lung function in the past, and even life-threatening. 9, phlebitis: the vast majority of chemotherapy drugs are administered intravenously, can cause varying degrees of phlebitis, lesions of the blood vessel color becomes dark red or dark yellow, local pain, touching the stripes, serious cases can lead to embolic phlebitis, the occurrence of obstructed blood flow. 10, neurological toxicity: mainly refers to the chemotherapy drugs on the peripheral peripheral nerve damage, patients can appear numbness of the extremities, limb sensory dullness, etc. 11, hepatotoxicity: almost all chemotherapy drugs can cause liver function damage, and in mild cases, liver function abnormalities can occur, and patients can experience discomfort in the liver area. Even this can lead to toxic hepatitis. How to reduce the side effects of chemotherapy? Because of the inevitable side effects of chemotherapy, chemotherapy patients must be routinely examined for routine blood tests, blood biochemistry, liver and kidney function, chest radiographs and other tests before chemotherapy, and routine blood tests, blood biochemistry, liver and kidney function should often be examined at the end and during chemotherapy, especially for patients who have had abnormalities in these tests. For treatment, drugs to reduce or reverse the above side effects, such as antiemetic drugs and immunity-enhancing drugs, are routinely given, and in serious cases, the dosage is reduced, the chemotherapy regimen is changed or the chemotherapy is stopped. The treatment of common side effects of chemotherapy for gastrointestinal tumor is as follows. 1. Pay attention to diet, encourage patients to eat high nutritious and easy to digest diet, small amount and many meals, forbid greasy and stimulating food, pay attention to replenish water when diarrhea. Those who eat less can be supplemented by intravenous nutrition. If there are oral ulcers, daily hydrogen peroxide should be washed to remove the pus from the oral ulcers, then saline gargle, Viscum aqueous (vitamin B complex solution) external spray ulcers, healing well. During chemotherapy, patients are advised to gargle with concentrated saline and Dopey’s solution several times a day to keep the mouth clean and prevent oral infection. Give symptomatic treatment such as anti-emetic and anti-diarrheal in time to promote patients’ recovery as soon as possible. 2, patients should not gargle with cold water and into cold food to prevent inducing pharyngeal spasm or aggravate neurotoxicity, can take vitamin B1, B6 and ginsenoside rh2, etc. 3, eat more bitter melon, mung bean sprouts, tea, shiitake mushrooms, fungus foods such as wood ear and monkey mushrooms, eat more vitamin-rich fruits such as kiwi, peach, apple, grapes, etc., drink more green tea, oolong tea, honey water. It can effectively reduce the liver damage caused by the side effects of chemotherapy.