When you go the doctor to get your blood pressure measured, you will hear two numbers, for example; 120/80. What do those numbers mean?
In order to understand the subject of blood pressure, we first have to know some information about the circulatory system (cardiovascular system).
The circulatory system is made up of organs that work together: the heart; lungs; blood vessels; and blood.
The heart, blood, and blood vessels make up the cardiovascular component of the circulatory system.
The heart is a muscle the size of your fist. It constantly pumps blood through the blood vessels. The blood carries oxygen and nutrients to the body’s organs and drops off waste products to be filtered out by the kidneys, liver, lungs, and skin.
Each heart beat pushes blood out of the heart into the arteries, then the heart relaxes while getting ready for the next pumping beat. So, in fact we observe two actions here: contraction and relaxation.
The contraction is called systole, and the relaxation: diastole.
The blood pressure is the amount of pressure exerted on your artery walls by the blood flowing into them, under the effect of the heart’s pumping action. Now let’s see, if the heart contracts to push the blood forward, this must be causing a higher pressure on the artery walls than when it relaxes, right? Exactly! So there are actually two readings for the blood pressure in one person: one while the heart contracts, which causes the higher pressure value: called systolic pressure; and the other when the heart relaxes/rests, called the diastolic pressure.
The systolic pressure is the upper/higher one, and the diastolic is the lower one.
Now let’s have a further look at the measurement unit of blood pressure. We say for example that my blood pressure is 120/80 mm of mercury. Which means that the blood presses on the walls of the arteries with the same pressure of a 1-mm thick column of mercury with the height of, say 120 mm, which is “the value we read”.
A sphygmomanometer and a stethoscope are devices used to record your blood pressure.
A sphygmomanometer consists of an inflatable cuff, a measuring unit (the mercury manometer, or aneroid gauge), and a mechanism for inflation which may be a manually operated bulb and valve or a pump operated electrically.
The cuff is normally placed to fit around an upper arm, at roughly the same vertical height as the heart while the subject is seated with the arm supported. It is essential that the correct size of cuff is selected for the patient. For clinical measurements it is usual to measure and record both arms in the initial consultation to determine if the pressure is significantly higher in one arm than the other. The cuff is inflated until the artery is completely occluded.
Using a stethoscope, we listen to the brachial artery at the elbow, the examiner slowly releases the pressure in the cuff. As the pressure in the cuffs falls, a “whooshing” or pounding sound is heard (see Korotkoff sounds) when blood flow first starts again in the artery. The pressure at which this sound began is noted and recorded as the systolic blood pressure. The cuff pressure is further released until the sound can no longer be heard. This is recorded as the diastolic blood pressure. We can also palpate/feel the radial pulse to make sure of the lower reading.
The top number (the systolic blood pressure) is considered a major risk factor for cardiovascular disease for people above 50 years of age. In most people, systolic blood pressure rises steadily with age due to increasing stiffness of large arteries and long-term build-up of plaque due to unhelathy eating habits and a sedentary lifestyle.
A single high reading does not necessarily mean that you have high blood pressure. However, if readings stay at 140/90 mm Hg or above (systolic 140 or above OR diastolic 90 or above) over time, this is a sign that you should start a treatment program. Such a program almost always includes lifestyle changes and often prescription medication for those with readings of 140/90 or higher.
If, while monitoring your blood pressure, you get a systolic reading of 180 mm Hg or higher OR a diastolic reading of 110 mm HG or higher, wait a couple of minutes and take it again. If the reading is still at or above that level, you should seek immediate emergency medical treatment for a hypertensive crisis.
Starting at age 20, it is recommended to do a blood pressure screening every 2 years.
Even if your blood pressure is normal, you should consider making lifestyle modifications to prevent the development of HBP and improve your heart health.
For more on blood pressure, please tune into iUnerstand.tv (afham.tv)
All the best.