For many of us, getting a blood pressure reading is a common occurrence – whether we’re at the doctor’s, having a routine health check-up or even as self-observation in the comforts of our own homes. While most of us may be familiar with the terms such as systolic and diastolic blood pressure, how many of us really understand what they mean?
And what exactly is blood pressure?
Blood pressure is the amount of pressure exerted against the walls of the body’s circulatory system’s blood vessels as the heart pumps – and is determined by the amount of blood pumped and the resistance of the artery walls. As the heart beats, it pumps blood into the large blood vessels and propels it around the body, creating a significant pressure on the walls of the blood vessels.
In short, blood pressure is the measure of force your heart uses to pump oxygenated blood around your body. As pressure is highest in the arteries due to their contractile capacity (flexibility and ability to self-contract), blood pressure is measured based on the arteries and is thus, also sometimes known as arterial blood pressure.
How to Read a Blood Pressure Monitor
Now that you understand blood pressure a little better, how do you actually measure it? These days, most people either have their blood pressures measured at the doctor’s or with the help of a digital blood pressure machine. Using a simple inflatable cuff, these machines are able to determine your reading in no time at all. But what do those words and numbers on the monitor even mean?
Systolic pressure (SYS) is the pressure created on the (blood vessels/arteries) when the heart beats as it contracts (squeezes) and pumps oxygen-rich blood around the body.
Diastolic pressure (DIA) is the pressure formed in the (blood vessels/arteries) when the heart relaxes between beats, allowing it to fill with blood and obtain oxygen. Since the heart is relaxed, the diastolic pressure is always lower in value compared to its systolic counterpart.
mmHg is the unit of measurement for blood pressure, and means millimetres of mercury. This is because mercury was the substance used in the first accurate pressure gauges, and while they may not be used anymore, mmHg remains a standard unit of measurement for blood pressure in the field of medicine.
Pulse (PUL) refers to the number of heart beats and is usually calculated per minute (PUL/min). However, not all blood pressure monitors have this.
Fun fact: Did you know that diastole and systole actually refer to the two phases of the cardiac cycle? That’s why blood pressure values are called systolic and diastolic pressure! If you have a hard time remembering the difference, just think of the S in Systolic as Squeeze, and the D in Diastolic as Decrease (lower value).
When reading your blood pressure, the numbers are always read in pairs like a fraction, with the systolic value (top) followed by the diastolic value (bottom). An example is 120/80 mmHg which is read as “120 over 80”. This means a person has a systolic blood pressure of 120 mmHg and a diastolic blood pressure of 80mHg.
Although blood pressure is read in pairs, systolic pressure is usually considered to be more important, especially as a risk factor for cardiovascular diseases for people over the age of 50. This is because systolic pressure tends to rise with age due to the structural changes of the arteries including plaque build-up and increased stiffness.
Diastolic pressure on the other hand, has a varying pattern with age where it tends to first increase up to about the age of 50, before slowly decreasing over time.
The Meaning Behind Your Blood Pressure Values
But what is considered normal blood pressure, and when should I start to worry?
Credit: Clinical Practice Guidelines, Management of Hypertension [4th ed.], Ministry of Health Malaysia
For most adults, normal ranges from a systolic pressure between 90 mmHg and 120 mmHg and a diastolic pressure of between 60 mmHg and 80 mmHg. Anything else is a cause for concern as numbers above the ideal range can indicate an issue that your heart is struggling to pump blood to the rest of your body, and a lower range can indicate an issue with low blood pressure (hypotension).
A more major problem, however, is the issue of hypertension – high blood pressure. As hypertension significantly increases the risk of cardiovascular problems such as heart attacks, strokes, kidney failure and more, managing blood pressure is key in maintaining one’s overall health.
In fact, according to the National Health and Morbidity Survey in 2019, up to 1 in 3 Malaysian adults suffer from hypertension. This means that roughly over 7 million people in Malaysia alone have hypertension, with many unaware of their condition – making it a clear cause for concern.
If you suspect you may be suffering from hypertension or even hypotension, be sure to visit your nearest doctor or health clinic as soon as possible. With so many affordable digital blood pressure monitors now easily available, regular checks at home is no longer an obstacle.
In fact, why not get your own blood pressure monitor now.
Reply to Shota Arita :
Please refer to the steps below on how to switch the Unit of Measurement:
1. Make sure the machine is off.
2. Long press “On/Off” Button for 10 to 15 seconds until it appear the 0.0 mmHg / 0.0 kPa.
3. Press “On/Off” Button to turn off the BP machine.
I bought a BP monitor, model No.:BSX556 and I can’t change from kPa to mmHg. I found the same question in a comment on Youtube, but I can’t find the answer anywhere.