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How are “high pressure” and “low pressure” formed?
A middle-aged friend is consulting with him in the background. Both he and his father have high blood pressure. He himself has high “low pressure” and “high pressure” is normal. High and “low pressure” are normal. He’s heard people say that in high blood pressure, “low pressure” is more dangerously elevated. Is it really?
In fact, the “high pressure” and “low pressure” in blood pressure are actually two independent risk factors, whichever is elevated is dangerous. However, if you have to compare, the danger of “high pressure” rising is greater.
1. How are “high pressure” and “low pressure” formed?
The “high pressure” in blood pressure (ie, systolic) refers to the pressure in the blood vessels when the heart contracts. When the heart contracts to pump blood, the body’s arteries are elastic and expand to accommodate blood. At this time, the maximum pressure of blood on the arterial wall is “high pressure”.
The “low pressure” (ie diastolic) in blood pressure refers to the pressure within the blood vessels of the heart when it relaxes. The heart stops pumping blood during diastole, and the large arteries that have just expanded during systole begin to retract under their own elasticity, continuing to push blood flow. At this time, the lowest value of the arterial wall pressure on the blood is the “low pressure”.
When the aorta is hardened, its elasticity decreases, its ability to expand and accommodate blood is weakened, and the heart needs to use more force to pump blood out, which is called “high pressure” rise. Arteriosclerosis is common in senile hypertension, and because of arteriosclerosis, the ability to expand is reduced, and the rebound force during diastole will be reduced, and the “low pressure” is normal or decreased.
When the peripheral small arteries contract and spasm, the resistance of the large arteries increases during elastic recoil, which is manifested as an increase in “low pressure”. However, if the large arteries are not hardened at this time, they can expand to accommodate blood normally. At this time, the resistance of the heart to pump blood is not large, and the “high pressure” is normal. This condition is common in young and middle-aged people with high blood pressure.
2. Hypertension can be divided into 3 cases
The first type, the “high pressure” is normal, and the “low pressure” is increased. This kind of blood pressure is common in young and middle-aged hypertension. The elasticity of the large arteries is normal, but the “low pressure” increases due to the contraction of peripheral small arteries and the increase of resistance. At this stage, after actively controlling blood pressure and eliminating the contraction of peripheral arterioles, it is possible to restore normal blood pressure.
Second, “high pressure” and “low pressure” rise at the same time. This type of blood pressure is called “classic hypertension”, which means that the resistance of the heart to pump blood and the resistance of peripheral arterioles are increased. At this time, the function of the heart and the elasticity of the arterial system are acceptable. By maintaining regular medication for a long time, blood pressure can be controlled and complications can be prevented.
The third type, “high pressure” rises, and “low pressure” is normal. This type of blood pressure is a typical feature of senile hypertension, indicating that the degree of arteriosclerosis is high, and sufficient “low pressure” cannot be maintained, and the blood supply capacity to the heart, brain, kidney and other organs is reduced. In this stage, the sensitivity of blood pressure to antihypertensive drugs is reduced, and it is a stage with high incidence of hypertension complicated by diseases.
3. Which one is more dangerous, “high pressure” or “low pressure”?
Relevant studies have shown that every 10mmHg increase in “high pressure” or every 5mmHg increase in “low pressure” will increase the incidence of cardiovascular and cerebrovascular diseases by 50%. That is to say, “high pressure” and “low pressure” in blood pressure are two independent risk factors, and their risk levels are basically the same. However, the increase of “high pressure” is common in the elderly, and the diseases caused by it are also more serious, so in fact, the risk of increased high pressure is greater than that of “low pressure”.
Actually, the pulse pressure difference obtained by subtracting “low pressure” from “high pressure” can better represent the risk of hypertension. The pulse pressure difference of normal blood pressure is between 30 and 40 mmHg, the lowest is not less than 20 mmHg, and the highest is not more than 60 mmHg.
If the pulse pressure difference is less than 20mmHg, it means that the peripheral resistance is very large and the blood supply to the vital organs is insufficient. When the pulse pressure difference is greater than 60mmHg, it means that arteriosclerosis has occurred. The higher the pulse pressure difference, the harder the blood vessel, and the more dangerous it is.
Four. Summary
To sum up, whether the “high pressure” rises or the “low pressure” rises, the degree of danger of both is the same and needs to be actively controlled. Most people’s hypertension develops along the line of “young and middle-aged hypertension – classic hypertension – senile hypertension”. The earlier the treatment, the greater the benefit. Everyone must pay attention to their blood pressure and protect their health.
Source of this article: Pharmacist Hua Zi
Editor in charge: Yuan Xueqing, Zhang Li
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