Arterial blood pressure is affected by many factors, such as blood volume and output per beat. After a patient with high blood pressure donates blood, the blood volume decreases and the patient may experience a decrease in blood pressure, but this does not last long. In general, it is not recommended that patients with high blood pressure donate blood blindly. Patients with high blood pressure need to take antihypertensive medication to control their blood pressure. If the medication is present in the patient’s body at the time of blood donation, the patient may easily become hypotensive due to the effect of the medication and the decrease in blood volume. If the patient donates too much blood, the blood volume will decrease rapidly, which may cause the coronary artery to spasm and lead to angina pectoris. In addition to active treatment of hypertension as prescribed by the doctor, patients need to change their daily habits to control their condition. Patients with hypertension are advised to reduce sodium intake, quit smoking and alcohol, control weight, and eat foods rich in vitamins and dietary fiber, such as oranges and grapefruit, to promote recovery.