How to Measure Blood Pressure

It is important to measure blood pressure periodically so as to know when it can be high or low. High Blood Pressure, better known as Hypertension is a medical condition whereby the pressure of blood inside the body is raised or high. What this means is that there is a normal blood pressure, a high blood pressure and a low blood pressure.

In this write up, we would be talking about how to measure blood pressure and also tell which one is high or low.

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How to catch High Blood Pressure early:

To prevent or reduce your risk of developing the damages that comes with the complications of hypertension, it is essential to detect this increase in blood pressure on time before it causes any real damage.

Don’t be scared, hypertension is very easy to diagnose. It only takes a few minutes to have your blood pressure checked and it is not a painful procedure. Nobody is piercing any needle or injection into your body.

Screening is the most effective way to catch essential hypertension early, but you need to make yourself available. Hospitals and other health facilities make it a policy to measure the blood pressures of everybody that comes to them. So if you find yourself in a hospital and your blood pressure is not measured, you can ask for it to be measured.


Where can i check or Measure Blood Pressure

You can also walk into any health center near you and ask for it to be measured. Some pharmacies and other health outlets also offer blood pressure monitoring services. You can also walk in and request for their services, if you are friendly you can get it checked for free, but most times it would cost some change.


How do they measure blood pressure?

The blood pressure is measured using an instrument known as the sphygmomanometer, with the help of another instrument known as the Sethoscope. The sphygmomanometer is used to record the pressure, while the sethoscope is used to listen for the sound of the movement of blood.


measure blood pressure
A nurse about to measure blood pressure of a woman at a market outreach

To do measure blood pressure of a person, a cuff would be put around your arms and inflated (that is, it is pumped). You would feel some pressure on the arms but it is not painful. Then the reading on the sphygmomanometer at the point where the first and the last sound are heard on the sethoscope are recorded down. That is the blood pressure.

Ideally, the practice is to measure blood pressure in both the arms and in the legs, but at least get it measured first even if it is in one arm. Blood pressure is measured in millimetres of mercury (mmHg). The readings would consist of two numbers in the form 120/80 mmHg.

The top number is known as the systolic blood pressure and indicates how much pressure your heart is working against to force blood to every part of your body. The bottom number is known as the diastolic blood pressure and indicates the force of blood on your blood vessels when your heart relaxes.

Your pulse may also be measured by fingers pressed around your wrists to find out how fast your heart is beating. Some electronic blood pressure monitors measures both the blood pressure and the pulse and displays the result digitally.


Example of Electronic Sphygmanometer used to measure blood pressure. Image Credit: Havard Health

However, the manual ones are preferred as some electronic sphygmomanometer may have errors.


Tips to help with blood Pressure measurement


  1. Don’t drink a caffeinated beverage or smoke during the 30 minutes before the test.
  2. Sit quietly for five minutes before the test begins.
  3. During the measurement, sit in a chair with your feet on the floor and your arm supported so your elbow is at about heart level.
  4. The inflatable part of the cuff should completely cover at least 80% of your upper arm, and the cuff should be placed on bare skin, not over a shirt.
  5. Don’t talk during the measurement.
  6. Have your blood pressure measured twice, with a brief break in between. If the readings are different by 5 points or more, have it done a third time.
  7. It’s also a good idea to have your blood pressure measured in both arms at least once, since the reading in one arm (usually the right) may be higher than that in the left.

Tips from Haverd Health


When is the blood pressure said to be high?

 In adults the blood pressure is said to be:


  • Normal: when the  blood pressure is less than 120 mmHg systolic and 80  diastolic
  • Elevated blood pressure: 120-129mmHg systolic and less than 80mmHg diastolic
  • Stage 1 hypertension: 130-139mmHg systolic or 80-89mmHg diastolic.
  • Stage 2 hypertension: 140mmHg and above systolic  or 90mmHg and above diastolic
  • Hypertensive crisis: 180mmHg and above systolic or 120mmHg and above diastolic

Basically if your blood pressure is higher than 120/80mmHg you should visit a doctor to discuss management options.


When is the blood pressure said to be low?

Unlike hypertension which does not show any symptoms or signs, when your blood pressure is too low (hypotension) you will definitely know. However, hypotension is not common and is mainly seen during treatment of hypertension when the individual takes more hypertensive drugs than he or she needs.

There is no absolute cut off value for hypotension but when it is lower than 90/60mmHg and it is not your usual readings, you would need to be careful especially if you are on hypertension drugs.


What do i do if i have high or low blood pressure?

If your measure blood pressure and the blood pressure is higher than 120/80mmHg you should visit a doctor to discuss management options. Also, you should also watch out for low blood pressure too, especially if you are on drugs for hypertension.

The symptoms of low blood pressure includes; dizziness, fainting, blurred vision, cold skin, sweating and lack of concentration.

When you notice any of these symptoms, you should come to the hospital and see a doctor, because, Hypotension can kill faster than hypertension.

Reviewed By:


  • Anigbo-igwe Ngozi

    Nrs. Anigbo-igwe Ngozi holds a Bachelors in Nursing Degree from the University of Nigeria, in Enugu. She currently works at Poly Clinic in Enugu State, Nigeria.

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