With the increasing knowledge of people’s medical and health care, people are more and more concerned about their own health. A number of people are also very concerned about whether their blood pressure is normal and whether they are suffering from hypertension? The World Health Organization (WHO) recommends the use of blood pressure criteria that a systolic blood pressure ≥ 140 mmHg and/or a diastolic blood pressure ≥ 90 mmHg without antihypertensive medication is diagnosed as hypertension. Patients with a previous history of hypertension who are currently taking anti-hypertensive medication should also be diagnosed with hypertension even though their blood pressure has fallen below 140/90 mmHg. In order to diagnose hypertension, the blood pressure must be measured several times and the average of at least two consecutive blood pressures must meet or exceed the above criteria. If the blood pressure is elevated only once, the diagnosis cannot be confirmed, but the patient must be followed up and observed.