1. Age: the incidence has a tendency to increase with age, and the incidence is high in people over 40 years old.
2. Salt: those who consume a lot of salt have a high incidence of hypertension, it is believed that salt <2g/day, almost no hypertension; 3-4g/day, 3% incidence of hypertension, 4-15g/day, 33.15% incidence, >20g/day incidence of 30%.
3. Body weight: obese people have high incidence.
4. Heredity: about half of hypertensive patients have 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 cities than in rural areas.
Blood pressure regulation mechanism
Multiple factors can cause blood pressure rise. The heart's ability to pump blood is strengthened (e.g., increased contractility of the heart, etc.), resulting in an increase in 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 out 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.
On the contrary, if the heart's ability to pump blood is limited, blood vessels dilate, or excess body fluids are lost, this can lead to a decrease in blood pressure. These factors are largely regulated by changes in kidney function and the autonomic nervous system (the part of the nervous system that automatically regulates many body functions).