Checking Blood Pressure

What is Blood Pressure and How to Check it at Home

People must understand the importance of checking blood pressure (BP) regularly since about “one-third” of the adult population is living with high BP. High BP may lead to cardiovascular events like a heart attack or stroke. The only way to identify this in early stage is regular blood pressure monitoring, as many individuals do not have any symptoms. That is why high blood pressure is also called the “silent killer.”

What is Blood Pressure, and How is it Measured?

Checking Blood Pressure
Blood pressure checking

It is the measure of pressure under which blood runs in blood vessels, but what is confusing for many that why are there two readings, what is systolic and diastolic blood pressure.

Heart beats in the chest, it contracts and expands. When its contracts, it sends blood rushing with maximum pressure, to the whole body, exerting higher pressure on the walls of blood vessels. This higher pressure is called systolic, as indicated by the higher reading of measuring equipment.

The relaxation phase follows the contraction. It is the time when the heart takes (gets filled by) oxygenated blood from the lungs. During this phase, there is a little fall in pressure in the arteries. Lower value shows this pressure during the relaxation phase, and it is called diastolic pressure.

Blood pressure is measured in mmHg. It means millimeters of mercury. Manual blood pressure machines still use this scale. Electronic devices do not have mercury, but they are calibrated to the scale of mercury.

Higher BP puts undue pressure on the blood vessels (the pipeline), the heart (the pump), and kidney (the filter). Prolonged and uncontrolled high-pressure in the circulation system may cause a breakdown at different levels, as compensatory mechanisms cannot keep managing forever.

Normal blood pressure is Systolic below 120 mmHg and Diastolic below 80 mmHg.

What is High Blood Pressure?

If someone’s reading is continually or frequently above 120/80 mmHg (either systolic or diastolic), it is a reason for concern. Many people may have isolated systolic or diastolic BP in the beginning.

Below is more information about how blood pressure is classified – see the table below.

Normal blood pressure & hypertension, as per the American Heart Association
Normal blood pressure & hypertension, as per the American Heart Association

So, hypertension is when at least three readings taken in a relaxed state show systolic pressure above 140 mmHg or diastolic above 90 mmHg.

This is revised and latest recommendation/classification, and as one can see that it includes a so-called yellow zone (elevated) when systolic blood pressure is between 120-129 mmHg and diastolic is less than 80 mmHg. It means that a person still does not have hypertension, and it is a chance to reduce blood pressure without medications – through lifestyle changes like reduced salt intake, exercise, and stress management. You can read more about foods that lower BP here.

What is Low Blood Pressure?

Unlike the western world, in India, many may have just an opposite complaint, that is of low blood pressure, dizziness, and weakness. It is especially more common among females.

Low BP is readings below 90 (systolic)/60 (diastolic) mmHg.

It is also a reason for concern, as it may indicate malnutrition or the presence of some chronic condition. Due to a higher rate of anxiety, women are more likely to complain about the condition in India.

Typical Daily Blood Pressure Fluctuations

It is essential to know that blood pressure does not remain constant during the day. Usually, it is at the lowest in the morning, just after waking. However, BP may increase during the day multiple times in response to stress.

Blood pressure fluctuations during the day
Blood pressure fluctuations during the day

This means that one cannot make conclusions based on a single reading. In some circumstances, your doctor might ask you to take your blood pressure a few times a day to see if the readings are consistent or not. Additionally, it is necessary to know about “whitecoat syndrome” – a rise in blood pressure when measured by a doctor due to anxiety.  This is just one of the reasons why multiple readings at home are the best way to know about the status.

Checking Blood Pressure at Home – Why it is Important?

Having a home BP Monitor is important for people who are at risk of certain cardiovascular and metabolic conditions. The higher your blood pressure, the greater the risk of you suffering from health issues in the future. Elevated BP puts strain on the heart and on your arteries, and over time that strain can cause the arteries to become thicker, reducing circulation, and increasing the risk of a stroke, a heart attack, and even other health conditions such as kidney disease and dementia. Your circulatory system is a vital part of your overall health.

Most people get their BP checked during regular visits to the doctor, but there are other ways for checking blood pressure – including having it checked at the pharmacist, or monitoring your blood pressure at home. If your doctor has recommended that you monitor your blood pressure on an ongoing basis, then it’s a good idea to get into the habit of checking blood pressure using a home monitor.

Checking blood pressure regularly at home has many benefits. This will help with an early diagnosis of the condition. It may provide more abundant data for clinicians to make decisions. It may also help exclude specific phenomena like Whitecoat syndrome, thus helping avoid false diagnoses.

Additionally, regular monitoring at home raises awareness, helps avoid wrong assumptions. It may sometimes help prevent more severe complications, especially in individuals prone to “hypertension crisis.”

Some people are prone to hypertension crisis – that is sudden and abnormally high upsurges in the blood pressure, thus considerably increasing the risk of heart attack or stroke.

Tips for Checking Blood Pressure at Home

Your blood pressure is not a static measure – there are a number of things that can affect it and make it rise for a short period. For example, your blood pressure might rise because of:

  1. Stress
  2. Exercise
  3. Caffeine Consumption
  4. Cold weather
  5. Smoking
  6. Medication

If you want an accurate measure of your blood pressure, take it when you are comfortable. Here are some of the essential recommendations from American Heart Association for checking blood pressure at home.

  1. Choose the right kind of BP monitor. It means of good manufacturer, as they usually test their equipment for accuracy. Do not rely on finger monitors, smartwatches.
  2. Ensure that cuff fits. Very loose or too tight cuff may give wrong readings.
  3. Right or left arm? There can be small individual differences, but a difference greater than 10 mmHg is a cause for concern.
  4. Keep a journal, or one can also use the app. Some BP Monitors are now coming with Bluetooth connectivity and can automatically record data to an app, thus taking out all the hassle.
  5. Measure blood pressure at the same time of the day. For hypertensives or prone to hypertensive crisis, it is good to take multiple measures in a day. One can measure in the morning and evening – but not necessarily.
  6. Avoid smoking, drinking alcohol, or caffeinated drinks before measuring.
  7. Find a quiet room and sit down and take a moment to calm yourself.
  8. Remove any tight-sleeved clothing. Taking measurement over the cloth is not advisable.
  9. Sit correctly with a straight back (like on a dining chair, and not on the sofa), do not cross your
    Correct position
    Correct position                               Position of Arm Cuff

    legs, support your arm on a surface like a table. Ensure that arm is at the level of the heart, and palm is facing up.

Care and Maintenance for your Home Blood Pressure Monitor

Most modern blood pressure monitors are almost maintenance-free and is usable for years without any concern. However, do not forget to change batteries at regular intervals. Also, ensure that the cuff is in proper condition.

  1. Press the start button only after wrapping the cuff around your arm.
  2. Keep the monitor away from devices like television, microwave ovens, X-ray device etc. as these devices have strong electrical fields.
  3. Don’t place the arm cuff around sharp objects.
  4. High temperature and direct sunlight are harmful to monitor.
  5. If you are not using your monitor for more than 2 weeks, remove the battery from monitor. This will prevent battery leakage and further damage to the internal parts of your monitor.

If there are doubts about the accuracy of equipment, one can visit a doctor or clinic and get a checkup. However, it would not be rare to have a little higher reading in the doctor’s office.

If there is no pressing reason, do not worry about the accuracy of your digital BP Machine. In India, there is wrong information among many that digital devices are not very accurate. On the contrary, they are highly precise as there is not much involvement of human factor. They may give errors only in the case of specific heart diseases like arrhythmia.

Published by

Dr. Aleksandar Grbovic

Dr. Aleksandar Grbovic

Hi! My name is Aleksandar Grbovic. I’m a radiology resident with five years of experience in General Medicine. As a medical writer, I have only one goal in my mind - to bridge the gap between doctors and patients point of view by breaking down complex medical topics and presenting them in lay people language. Knowing that my writing might help someone out there connect the dots is what keeps me motivated.

  1. John October 22, 2017

    The information provided here are very very important because the rise in blood pressure increases the risk for more health problems. Also high BP will damage your blood vessels and heart in long run.

    good luck and cheers!

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