Normal blood pressure values are systolic blood pressure <140 mmHg and diastolic blood pressure <90 mmHg. Hypertension is defined as a systolic blood pressure ≥140 mmHg or diastolic blood pressure ≥90 mmHg. A systolic blood pressure of 90-139 mmHg and a diastolic blood pressure of 60-89 mmHg are called normal blood pressure values. The prevalence and incidence of hypertension varies significantly between countries, regions and races. There are regional urban-rural and ethnic differences in the prevalence and prevalence of hypertension in China, which increases with age, with the north being higher than the south, north and northeast China being among the high prevalence areas, the coast being higher than the interior, the cities being higher than the countryside, and the highland minority areas having a higher prevalence. The overall prevalence of hypertension in men and women does not differ significantly, with males slightly higher than females in youth and females slightly higher than males after middle age.