Blood pressure is measured in mmHg, with high blood pressure of 140 mmHg and low blood pressure of 110 mmHg requiring medication as prescribed by a physician. Hypertension is defined as three measurements of blood pressure that are above normal, i.e., systolic blood pressure ≥ 140 mmHg, and/or diastolic blood pressure ≥ 90 mmHg, without antihypertensive medication, and these three measurements are not taken on the same day. A high blood pressure of 140 mmHg and a low blood pressure of 110 mmHg is considered hypertension and therefore needs to be treated with medication. In case of primary hypertension, on the basis of improving lifestyle, the doctor will judge whether to give antihypertensive medication or not, and common antihypertensive medications include metoprolol, captopril, nifedipine and so on. In case of secondary hypertension, symptomatic treatment is needed according to the cause.