What is Hypertension or High Pressure and how does it occur?
Hypertension or high blood pressure is a disease that usually comes unannounced, it actually often hides, quietly, which is why it’s also known as the “silent killer”.
A person may not know they have hypertension until they suffer a heart attack or stroke; that’s why it’s very important for you to check your blood pressure periodically.
With a simple checkup, you’ll be able to know if you have hypertension, and the doctor will be able to take all necessary steps to control it avoiding further problems.
Checking your blood pressure is even more important if you have Diabetes. People with Diabetes are six times at more risk of developing hypertension that people without it.
Hypertension can cause kidney failure to appear more quickly if you already have kidney problems or diabetic nephropathy, and some experts also say that hypertension allows diabetic retinopathy, an eye Diabetic complication, to progress.
Hypertension damages the blood vessels; these small vessels feed all of the body’s organs, and the damage caused to them can affect your brain, heart, kidneys, etc. Eventually your doctor can diagnose hypertension and advise you to exercise, keep a proper nutritional regimen, change certain lifestyle habits and may prescribe some medication, but the rest is up to you.
How is blood pressure created?
With each heartbeat, blood is pumped from the heart to the blood vessels. First blood flows through the aorta (the largest artery in the human body), then it circulates through the vessels, which are smaller. The pressure that blood exerts depends on the amount of blood, blood vessel size and the strength and speed with which the blood is pumped by the heart. In people with hypertension, one or more of these factors isn’t normal.
The human body has about five liters of blood and half of it is made of salt and water. When the amount of water and salt increase, the volume of blood increases, therefore, blood pressure increases.
The kidneys and adrenal glands (which are located above the kidneys) regulate blood volume by regulating the amount of water and salt in it. Under normal circumstances, if a person eats too much salt and then drinks plenty of water, the kidneys will expel excess of both through urine. This causes blood water and salt volumes to remain at normal levels, therefore, blood volume and pressure on arteries and vessels don’t increase.
If, however, kidneys detect that blood volume is low, they send a signal to the adrenal glands to produce Aldosterone, a hormone that helps the kidneys limit salt and water expelled through urine, helping it increase blood volume.
Blood vessel size
Blood volume is an important factor that causes blood pressure to rise, but what’s even more important is the degree of resistance blood can gather on its way, while it flows through increasingly narrow vessels. Imagine a hose where water flows freely, it won’t exert any more strength in order to go out on the other end. Now imagine you place a cap or obstacle on the hose, in that case, the water must exert force and the pressure of it on the walls of the hose will increase.
This also happens with blood and increasingly narrow blood vessels, which exert more resistance on the blood, increasing its pressure.
Heartbeat strength and speed
There are other factors that increase blood pressure, which are the force and speed with which the heart pumps blood to the blood vessels. The faster and stronger the blood is pumped, the greater the pressure it’ll exert.
The heart and blood vessels are heavily influenced by the autonomic nervous system. This system controls the body’s processes that don’t require conscious actions, such as digestion, sweating, etc. The autonomic nervous system also affects blood pressure by causing the secretion of certain substances that alter the diameter of blood vessels and the heartbeat’s frequency and intensity.
Some of these chemicals cause the vessels to compress, allowing for increased blood flow resistance and increasing pressure, other chemicals also cause vessels to expand, thereby reducing blood pressure.
Other chemicals make the heart beat stronger and faster, which increases blood pressure. When a person is under stress, the autonomic nervous system triggers the secretion of adrenaline, increasing the heartbeat’s speed and strength and, therefore, blood pressure.