Bevacizumab side effects are as follows: 1. Serious adverse reactions: including gastrointestinal perforation, bleeding, arterial thrombosis, blood clots, bleeding types including tumor-related bleeding, skin mucosal bleeding; 2. Other adverse reactions: including abdominal pain, diarrhea, nausea, vomiting and other gastrointestinal reactions, as well as weakness, hypertension, proteinuria, congestive heart failure and other adverse reactions. Laboratory tests may show a decrease in neutrophil count and a decrease in white blood cell count. Patients need to contact their doctor promptly if they experience any discomfort during treatment. This drug is a prescription drug and must be used appropriately under the guidance of a physician. If you are using other drugs, please consult your doctor before use in order to prevent drug interactions from affecting treatment.