What is a BP Monitor and How does it Work?

Your blood pressure fluctuates because of your heart rate, diet, mood, or some illness.

Normal Blood pressure is less then 120/80 mmHg if you have your blood pressure above this reading you have high blood pressure.

High Blood pressure or hypertension is a common disease these days. It is causing so many people their healthy lives and their happiness.

People who are suffering from high blood pressure need to check their BP often, and Blood pressure Monitor does it. Not regularly checking the blood pressure; can cause further problems to your health.

Don’t know anything about BP Monitor? Don’t worry; I am going to tell you everything you need to know about BP Monitor.

What is BP Monitor?

BP monitor is a device that measures your Blood Pressure. It uses an inflatable cuff to put controlled pressure on your arteries and then release it slowly to measure the Blood pressure using a mechanical or digital manometer.

BP monitors are also called a Sphygmomanometer, BP meter, or BP gauge.

BP monitor is usually used by people with High Blood pressure, Preeclampsia, Pulsus alternuns, and Arrhythmia.

There are manual BP monitors that have clinical use and can only be used by trained doctors or nurses. Digital monitors are mostly used in home blood pressure monitoring. They don’t require any training for using the device.

BP Monitor

How does it work?

Manual BP monitors use the auscultation technique. First, the inflatable cuff is placed around your upper arm at the same height as the heart. As the examiner slowly releases the pressure, a sound from your Brachial artery can be heard through the stethoscope.

The pressure at which the blood started flowing again is called the systolic blood pressure. Then the examiner keeps releasing the pressure until the sound can not be heard; this is called diastolic blood pressure.

The systolic pressure is the upper reading, and the diastolic pressure is the other part. For example, if your Blood pressure is 130/80, then 130 is systolic pressure, and 80 is diastolic.

In noisy places whare, the auscultation can not be heard, only systolic blood pressure can be read by releasing the pressure until a pulse is felt.

Digital BP monitors use the oscillometric method. They also have a cuff that is placed around your arm, but instead of auscultation, they use electrical pressure sensors to determine the oscillation in the Blood flow.

In the inflation period, the cuff excesses the pressure in the systolic artery and then reduces to diastolic pressure in 30 seconds. The cuff pressure oscillates because of cyclic expansion and contraction of the brachial artery.

When deflation of the cuff starts, the readings from the cuff sensor form a signal known as the cuff deflation curve. Then a bandpass filter is used to extract oscillometric pulses. They form a signal called the oscillometric waveform.

An analysis algorithm can be used to estimate systolic, diastolic blood pressure.

Types of BP Monitor

Manual BP monitors

Manual BP monitors are mostly used for clinical diagnosis. It comes with an inflatable cuff to put pressure on your arm and mercury or aneroid manometer to measure your Blood pressure.

The manual BP meters are better than the digital meters in terms of accuracy. It is hard to use, so trained doctors or nurses mostly use it. Learn to use Manual and Digital Blood Pressure Monitor.

Now there are two types of Manual BP meters

  1. Mercury BP meters, also called the Baumanometer, are the most accurate meters. It gives Blood pressure readings by affecting the height of a column of mercury. Because of the accuracy, this BP monitor is often used in drug trials or the evaluation of high-risk patients. It doesn’t require any calibrations. Because of the safety concerns about the mercury, these BP monitors are not used in community settings.
  2. Aneroid BP monitors use a mechanical membraneĀ that translates the data coming from the cuff and gives the readings in a dial. They are now commonly in use. They require recalibrations, but they are safer than the mercury BP monitors.

Digital BP monitor

Digital BP monitors are easy to use; that is why they are recommended in Home Blood Pressure Monitoring. You can place the cuff of digital BP meters on your upper arm, wrist, or finger.

Digital BP meters may use a manual or automatic inflation, but both will be electronic.

They are less accurate in measuring systolic and diastolic BP than manual BP monitors, but they measure mean Blood pressure and pulse rate accurately.

They use the oscillation method to estimate your blood pressure.

Many factors affect the readings like Pulse rate, Heart rate, and arterial stiffness. Because of it, it is advised to not to use with patients who haveĀ arteriosclerosis, Arrhythmia, Pulsus paradoxus, Preeclumsia, and pulsus alternans as their condition can alter the BP readings.

I have also posted an article about the best blood pressure machine in India, check it out if you want to buy a Digital Blood Pressure Monitor.

If you are not sure which one to buy, I have compared Manual and Digital BP Monitor in this Article.

Home Blood Pressure Monitoring(HBPM)

Self-measurement of Blood Pressure is an essential tool in controlling your high Blood pressure. At home, you can get the results more often and compare them with the previous results to see the progress.

You can see the change in your health caused by your daily habits, diet, or mood.

Many studies have shown that HBPM can improve your blood pressure control, reduce Whitecoat hypertension, and indicate warnings for cardiovascular risk.

It is cheaper than hospital tests.

You can see if the medication you are taking is working correctly. Home Blood pressure Monitoring can improve your lifestyle to improve your health.

It is advised by the American heart association to use a digital BP meter with an automatic inflatable cuff that fits your upper arm. It is easy to use at home.

I would suggest you to go through Is it worth Buying BP Monitor and decide for yourself.

In the end

So if you have high blood pressure, then you need to get your Blood pressure checked regularly. Precautions are better than long term and costly treatments.

How many times to check? Or When to test? You can discuss that with your doctor and start the treatment that you need.

Checking your BP properly will give you the idea of how to control your high blood pressure to get better, and a BP monitor will help you with that.


  1. Home Blood pressure Monitoring– NCBI
  2. Sphygmomanometer-Wikipedia
  3. American heart association

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