Bysentin is a calcium channel blocker, which can dilate blood vessels and lower blood pressure. It is clinically indicated for patients with various types of hypertension. In the process of application, there is a possibility of side effects, which may cause allergic reactions, mainly edema, angioedema, including head edema, itching, urticaria, rash, and allergic reactions in other areas. In addition, it may lead to granulocytosis and leukopenia. It may also cause anxiety, abnormal sleep, and elevated blood sugar due to disorders of glucose metabolism. Then there is the possibility of headache, dizziness, lightheadedness, dullness of sensation, and drowsiness. There may be visual abnormalities, eye pain, and reflex tachycardia. Then there is the possibility of causing bilateral lower extremity edema. It may also trigger upright hypotension, and there will be gastrointestinal symptoms, such as nausea and indigestion.