I. Definition of hypertension: In the absence of anti-hypertensive drugs, systolic blood pressure ≥ 140 mmHg and, or diastolic blood pressure ≥ 90 mmHg, divided into 1, 2, 3 levels according to blood pressure level, equivalent to mild, moderate and heavy hypertension. Patients with a previous history of hypertension, currently on anti-hypertensive medication, should also be diagnosed with hypertension although their blood pressure is lower than 140/90 mmHg. If the patient’s systolic blood pressure and diastolic blood pressure belong to different levels, the higher level will prevail. Category Systolic blood pressure (mmHg) Diastolic blood pressure (mmHg) Normal blood pressure ＜120 ＜80 Normal high value 120～139 80～89 Grade 1 hypertension (mild) 140～159 90～99 Grade 2 hypertension (moderate) 160～179 100～109 Grade 3 hypertension (severe) ≥180 ≥110 Simple systolic hypertension ≥140 ＜90 Three, the hypertension Risk stratification: The absolute risk level of hypertensive patients was stratified using the combination of cardiovascular risk factors, target organ damage and related cardiac, cerebral, renal and vascular complications, and was divided into four categories: low risk, intermediate risk, high risk and very high risk. 1, low risk: hypertension grade 1 with no other risk factors; 2, intermediate risk: hypertension grade 1 with 1-2 risk factors, or hypertension grade 2 without or with no more than 2 risk factors; 3, high risk: hypertension grade 1-2 with at least 3 risk factors; 4, very high risk: hypertension grade 3 or hypertension grade 1-2 with target organ damage and related clinical diseases (including diabetes).