According to the diagnostic criteria for hypertension, patients with a low pressure (diastolic) of 90 are considered mildly hypertensive. Hypertension was diagnosed if the systolic blood pressure was ≥140 mmHg and/or diastolic blood pressure was ≥90 mmHg when the blood pressure was measured once a day for three days, respectively, in the absence of antihypertensive medication. Patients with a previous history of hypertension, who have received regular blood pressure lowering treatment, were diagnosed with hypertension despite a blood pressure <140/90 mmHg. Blood pressure levels in the population are continuously normally distributed, and there is no clear boundary between normal blood pressure and elevated blood pressure, and the criteria for hypertension are defined based on clinical and epidemiological data. (Chinese hypertension prevention and treatment guideline criteria: Currently, China uses normotension (systolic blood pressure <120 mmHg and diastolic blood pressure <80 mmHg), normal high [systolic blood pressure 120-139 mmHg and/or diastolic blood pressure 80-89 mmHg] and hypertension [systolic blood pressure ≥140 mmHg and/or diastolic blood pressure ≥90 mmHg] for blood pressure level classification.) Based on the level of elevated blood pressure, hypertension was further classified into three levels: 1. Class hypertension (mild) as systolic blood pressure 140~159 mmHg and/or diastolic blood pressure 90~99 mmHg; 2. Class hypertension (moderate) as systolic blood pressure 160~179 mmHg and/or diastolic blood pressure 100~109 mmHg; 3. Class hypertension (severe) as systolic blood pressure ≥180 mmHg and/or diastolic blood pressure ≥ 110 mmHg. (Note: When systolic and diastolic blood pressure belong to different levels, the higher classification prevails) The above criteria apply to men and women over 18 years of age, while children use the 95th percentile of blood pressure values for different age groups, which are usually lower than adult levels. It should be noted that the above blood pressure values are office blood pressure, and in the case of home self-measured blood pressure, the diagnostic criteria for hypertension is ≥135/85 mmHg, which corresponds to the office blood pressure of 140/90 mmHg. The diastolic blood pressure of a patient with an office blood pressure of 90 is considered mild hypertension. Treatment depends on whether there is a combination of clinical disease and risk factors. If there is no combination of clinical disease and risk factors, the patient is at low risk and treatment is based on lifestyle improvement. If there are risk factors or comorbid clinical disease, pharmacological treatment needs to be initiated.