The main reasons for vomiting during m2a chemotherapy for acute leukemia are drug factors, eating during chemotherapy, and psychological factors. 1. Drug factors: chemotherapeutic drugs such as cytarabine will produce a certain stimulation of the gastrointestinal mucosa, which in turn stimulates the release of neurotransmitter 5-hydroxytryptamine, leading to nausea and vomiting. 2. Eating during chemotherapy: Eating greasy, rough and irritating food during chemotherapy can also lead to different degrees of vomiting. 3. Psychological factors: psychological factors such as past use of chemotherapy drugs and excessive anxiety about the adverse effects of chemotherapy can also lead to vomiting during chemotherapy. Vomiting during chemotherapy for acute leukemia m2a is the result of a combination of reasons. It is recommended to actively seek medical help before chemotherapy, and to receive antiemetic treatment under the guidance of a physician after vomiting occurs, and the medication includes tropansetron and so on.