1. Age: the incidence rate has a tendency to increase with age, and the incidence rate is high in people over 40 years old.
2. Salt: salt intake, high incidence of hypertension, there is a view that salt day, almost no hypertension; 3-4g / day, the incidence of hypertension 3%, 4-15g / day, the incidence of 33.15%, > 20g / day incidence of 30%.
3. Body weight: obese people have a high incidence.
4. Heredity: about half of patients with hypertension have a family history.
5. Environment and occupation: noisy working environment, over-stressful mental labor are prone to hypertension, and the incidence of hypertension is higher in urban than in rural areas.
Blood pressure regulation mechanism
A variety of factors can cause an increase in blood pressure. Increased pumping capacity of the heart (e.g., increased contractility of the heart, etc.) increases the amount of blood pumped out per second. Another factor is that the large arteries lose their normal elasticity and become stiff, so that when the heart pumps blood, they do not expand efficiently, so that the blood flow pumped out with each heartbeat passes through a narrower-than-normal space, resulting in higher pressure. This is the reason why high blood pressure occurs more often in older people whose arterial walls have thickened and become stiff due to atherosclerosis. Small arteries throughout the body can temporarily constrict due to stimulation of nerves and hormones in the bloodstream likewise causing an increase in blood pressure. A third factor that may cause an increase in blood pressure is an increase in the volume of fluid in the circulation. This is commonly seen in kidney disease, where the kidneys are unable to adequately remove sodium and water from the body, and the volume of blood in the body increases, resulting in higher blood pressure.