Hypertension classification is differentiated according to the patient’s blood pressure level, and the current clinical use standard is WHO standard or Chinese classification standard, which is mainly divided into the following grades: 1. Hypertension grade I: systolic blood pressure ≥ 140 mmHg, or diastolic blood pressure ≥ 90 mmHg; 2. Hypertension grade II: systolic blood pressure between 140-159 mmHg, or diastolic blood pressure of 90-109 mmHg; 3. Systolic blood pressure ≥ 180 mmHg, or diastolic blood pressure ≥ 110 mmHg. one of the systolic or diastolic blood pressure reached the highest, as the standard assessment.