To properly understand how pressure reduction plays an important role in the prevention of cardiovascular disease, it will be interesting to consider some physiological aspects of the cardiovascular system.
The length of blood vessels in our body is about 111 000 kilometers. With each stroke, 60-80 grams of oxygen-enriched blood gets from the ventricle of the heart to the aorta with strong pressure. The vascular system of the human body can be compared to a tree. The aorta is the trunk of this tree. It is branched into many arteries, which in turn are divided into smaller branches called arterioles. They carry blood capillaries – leaves of the tree. Blood capillaries are microscopic vessels that supply oxygen and nutrients to every cell in our body. After the transfer of oxygen to the cells, the blood returns to the heart through a network of venous vessels. To move the blood through the branched artery and vein system, you need to use a certain amount of force or energy. The force that affects the walls of blood vessels during the blood flow is what we call pressure. Of course, the strength of blood pressure depends on the work of the heart, but no less important in the regulation of blood pressure play an arterioles – the smallest arteries.
They can relax if you need to lower your blood pressure, or shrink if you need to raise it. The level of blood pressure varies from person to person and depends on their activity. For example, the heart does not need to work fast and hard when you rest. But if you are doing physical work or exercising, large amounts of blood are needed to supply oxygen to your muscles and your blood pressure starts to rise. In another situation, for example, if you rise sharply from a horizontal position, your body will respond with an immediate pressure boost to ensure a steady supply of oxygen to your brain. The blood vessels in the legs and abdomen contract and the heart starts to beat faster. Sometimes, however, there may be a slight delay in this response, and you may feel a slight dizziness or weakness. This happens especially often with older people, whose vascular reflexes are somewhat slower. Some people may feel “blurred” in the head or weakness if they are on their feet for a long time. This is due to the fact that blood accumulates in a kind of blood depot – leg veins, and as a result, the brain receives insufficient oxygen.
Arterial pressure is regulated by complex nervous and hormonal mechanisms and can vary significantly during the day. Usually, the blood pressure is lower when you sleep and, conversely, it increases during waking or stress. If you are frightened or irritated, your adrenals are beginning to produce the stress hormone, adrenaline. This hormone forces the heart to beat harder and more frequently, resulting in higher blood pressure and more blood flowing to your muscles. As it was found out, the blood pressure is usually lower between 1:00 and 5:00 a.m., rises sharply from 6:00 to 8:00, then practically does not change during day and evening time and falls from 11:00 to 12:00 at night. The pressure also varies with age. In children, normal blood pressure may be 70/50, and in older people it may be more than 120/80. What is the blood pressure made of? The number of heart beats is about 60-70 per minute and can increase up to 120-140 beats, for example, during sports activities.
As you know, the heart does not contract continuously, and each beat is followed by a short period of relaxation or rest. The blood pressure changes as a result: 120 over 80 or 120/80. The large number is called systolic pressure and refers to the highest blood pressure on the vascular wall after a heartbeat. The smaller number, called diastolic pressure, indicates the blood pressure at rest between heartbeats. How is hypertension diagnosed? A diagnosis of hypertension is usually not made after measuring the blood pressure alone, unless the blood pressure is too high, for example over 170-180/105-110. Usually, a series of measurements is taken over a certain period of time to fully confirm the diagnosis. The circumstances during which blood pressure measurements are taken should also be taken into account. Typically, blood pressure readings increase under the influence of stress, after a cup of coffee or a smoked cigarette. It is interesting that in the doctor’s office, when taking blood pressure measurements, your blood pressure may be higher than it actually is.