The correct way to take your blood pressure at home

 

 

By Ibironke Taiwo. Datelinehealth Africa Volunteer Freelance Writer, with editorial support from The DLHA Team

 

 

Introduction 

 

In the course of carrying out a clinical procedure, a patient once said to me, "I do not have blood pressure". The saying is common among Nigerian African patients and it is a misstatement to indicate that they do not have high blood pressure. 

 

Every living individual has blood pressure, which could be high, low, or normal.

 

High blood pressure also known as hypertension is the number one risk factor for cardiovascular disease. 

 

About 40% of adults in Africa have hypertension and data suggests that this figure might rise by 2025 due to lifestyle.

 

High blood pressure commonly does not have any symptoms, but if it is present in a patient and not treated or managed in time, it can lead to complications such as stroke, heart disease, etc. 

 

This is why it is necessary to know how to check your blood pressure so that if it is high or low you can then seek medical attention promptly.

 

This article will briefly explore what blood pressure is and detail a step-by-step guide on how to measure and interpret blood pressure readings.

 

What Is Blood Pressure? 

 

Blood pressure or BP for short, is the force exerted by circulating blood on the walls of the arteries. Arteries are blood vessels in humans that carry oxygenated (rich in oxygen) blood away from the heart to one or more parts of the body.

 

Blood pressure is measured in two numbers which are SYSTOLIC (the measurement taken when your heart pushes blood out) and DIASTOLIC (the measurement taken when your heart rests between beats).

 

In recording the measurement obtained from checking blood pressure, the systolic blood pressure comes first followed by the diastolic. For example; 120 (systolic value) over 80 (diastolic value) are typical normal blood pressure values.  

 

The unit for the measurement of blood pressure is mm Hg.

 

Instruments Used For Measuring Blood Pressure 

 

The sphygmomanometer also known as a blood pressure gauge, blood pressure meter, or blood pressure monitor is the standard instrument used to measure blood pressure and it is of different types (see figure. 1) that include:

 

1. Mercury Sphygmomanometer 

 

This type of sphygmomanometer is considered the "gold standard" for measuring blood pressure. It is the most used blood pressure measurement instrument at the hospital in most African countries. 

 

Its cuff is tied around the arm of the patient, and the inflation bulb is inflated to about 30 points above the normal systolic blood pressure (i.e. above 120 mm Hg). The air valve which was initially tightened is then gradually released to gently ease air out of the cuff.

 

Prior to releasing the air from the cuff, the earpiece of a stethoscope is placed into the ear and the bell part of the stethoscope is placed below the positioning of the cuff at the arm. 

 

During the release of the inflation, two sounds known as the Korotkoff sounds are heard. The sphygmomanometer number corresponding to when the first sound is heard is recorded as the systolic value while matching reading when the last sound heard is the diastolic value.

 

2. Aneroid Sphygmomanometer 

 

This sphygmomanometer has the same similarities to the mercury sphygmomanometer except for the presence of an aneroid manometer gauge in place of a column of mercury. The steps that are  performed when the mercury sphygmomanometer is used are the same as when the aneroid sphygmomanometer is used.

 

3. Digital Sphygmomanometer 

 

The digital sphygmomanometer which consists of the arm cuff and a digital or electronic blood pressure monitor is considered to be the best for checking blood pressure at home because it is easier to use compared to the Mercury Sphygmomanometer and Aneroid Sphygmomanometer.

 

 

The digital sphygmomanometer is also good for hearing-impaired patients as you don't have to place a stethoscope in your ears to hear the systolic and diastolic sounds, all of this will be displayed on the monitor that comes with the digital sphygmomanometer.

 

Step-By-Step Guide On How To Measure Blood Pressure At Home 

 

Due to the lack of symptoms exhibited by hypertension (high blood pressure), it is important to keep an eye on your blood pressure to detect any changes above normal as soon as possible. 

 

 

This is why you should know how to correctly measure blood pressure within the comfort of your home.

 

The focus of this article is how to check blood pressure at home and the best instrument chosen for that purpose is the digital sphygmomanometer.

 

 

This step-by-step guide on how to use the digital sphygmomanometer to take your blood pressure correctly are easy to follow.

 

 

 

Before you start to measure your blood pressure

 

• Avoid smoking, eating, drinking coffee or any caffeinated beverage, and exercising within 30 minutes of taking your blood pressure. These can raise your BP temporarily.

• Wear loose fitting dress such that your arm is freely available for the application of the cuff.

• Make sure that you are relaxed and comfortable. If you are anxious or uncomfortable, your blood pressure reading will rise temporarily.

 

 

 

How to measure your blood pressure step-by-step?

 

 

Step 1:

• Sit comfortably in a chair with a good back support.

• Remain in the position quietly for 3 to 5 minutes before checking your blood pressure.

• Place your feet flat on the floor and place your arm on a tabletop making it even with the level of your heart.

• Stretch out your arm with your palm upward on the tabletop .

 

Step 2:

 

• Insert or wrap the cuff on your bare upper arm (right or left; whichever suits you) one inch above the bend of your elbow. This is to ensure that the sensor in the cuff can properly detect the flow of blood in your arm vessel (artery). The artery lies just underneath the skin in the front of your arm.

• Make sure that the tubing of the cuff falls over the front center of your arm. 

• Make sure the cuff is tightened sufficiently so that you can pass say two fingers under the bottom edge of the tightened cuff.

• Uncross your legs if they are crossed before you start the monitor.

 

Step 3:

 

• Click on the start button below the screen of the monitor and wait for the cuff to get inflated automatically.

• Keep still and quiet as the cuff also deflates automatically and the blood pressure reading is displayed on the screen of the monitor. Moving, chewing, talking and laughing can affect your reading.

• The figures displayed on the monitor will consist of your blood pressure values, the heart or pulse rate, and the date / time the blood pressure was checked.

• Take two or three readings, about 1 -2 minutes apart. If the monitor fails to display a reading or your blood pressure is unusually high, simply restart the process after a wait period as earlier indicated.

 

Step 4:

 

• Keep a record of your blood pressure readings. Record the numbers you obtained from the monitor either in your diary or on an electronic device. This will help you keep a record of your blood pressure and you can also show it to your doctor when next you visit the clinic or hospital.

 

 

Watch the video below to see the above steps being performed by a human subject.

 

Clcik on image to watch video.
 

 

Tips for taking your blood pressure correctly at home

 

• Measure your blood pressure in both arms when you take it for the first time ever. You will likely get slightly different readings. After this first run, always use the arm that gave you the higher reading.

• Use the same arm each time. If possible, use the arm that your doctor or nurse uses when they measure your blood pressure.

• Take readings at the same time each day. This is important because blood pressure measurement can vary throughout the day and with different activities. It’s good to have a routine – like measuring your blood pressure before breakfast or before you go to bed at night. In this way, you can compare like with like daily.

• Record your measurements accurately as displayed on the monitor. Doing so helps to ensure that you get the best treatment for your condition.

• Don’t get anxious if you get an unexpected high reading. A one-off high reading is usually not an issue to worry about. If it happenes, rest for about three to five minutes and take the reading again. Repeat the process daily for a week or two. If it remains high during the period, talk with your doctor or nurse.

• Don’t check your blood pressure too often daily. As blood pressure may change from time to time daily, some people get worried or stressed out about these small changes when taken too often. Worrying can raise your blood pressure in the short term, making your reading higher than it should be.

• Speak to your doctor or nurse if you’re worried. If you have questions or concerns about your readings or home monitor, speak to your doctor or nurse. If you think you may be having a stroke or heart attack call for help immediately from a family member or the emergency call line in your location.

• Don’t stop taking your medications if your blood pressure falls. Always talk to your doctor before stopping your medications, even if your blood pressure has fallen to a healthy level according to your home monitor. 

 

 

Best Place for Measuring Blood Pressure; Home or Hospital?

 

Research indicates that home readings reflect the overall level of blood pressure more reliably than office readings (i.e., the doctor's office) because they are usually lower than office readings. Therefore they may be used as an alternative and cost-effective means of evaluating patients with mild hypertension.

 

Measuring blood pressure at home is chosen over measuring at the office due to the anxiety developed by some individuals when visiting a health care provider. An increase in blood pressure at a medical office compared to your home is called white-coat hypertension.

 

Nevertheless, when you are in the hospital, your blood pressure still needs to be checked and a comparison can be made between the values you had from home and the ones at the hospital for accuracy.

 

When Blood Pressure is Normal and Abnormal

 

Blood pressure values in the range of 90 to 120 mm Hg for systolic and 60 to 80 mmHg for diastolic are considered normal. 

 

According to the American Heart Association, blood pressure can be categorized into 5 groups. (See figure 2).

 

A normal blood pressure is lower than 120/80 mmHg and is read as 120 systolic over 80 diastolic or preferably 120 over 80.

 

If the blood pressure ranges from 120-129 over < 80 mm Hg, then it is said to be elevated.                                                                                                                                    

If it continuously ranges from 130-139 over 80-89 mmHg, this is referred to as Stage 1 hypertension.

 

At stage 2 hypertension, the blood pressure is greater than 140/90 and it becomes an emergency hypertensive crisis when it is greater than 180/120 mmHg.

Figure 2: Showing normal and abnormal blood pressure categories (American Heart Association, AHA).

 

High blood pressure is usually associated with the following controllable risk factors such as 

• Lack of enough physical activity
• Diabetes
• Obesity
• Smoking
• Alcohol use
• Poor sleep.

 

High blood pressure can also occur during pregnancy. 

 

The common complications that are associated with high blood pressure are:

• Stroke
• Heart attack
• Damage to blood vessels
• Vision and kidney damage.

 

Just as hypertension (high blood pressure) poses a health problem, hypotension (low blood pressure) is equally a health challenge.

 

Blood pressure values consistently below 90 mmHg systolic and 60 mmHg diastolic indicate low blood pressure. 

 

Hypotension is not usually common.

 

Common causes of hypotension include:

• Loss of blood due to bleeding.
• Dehydration
• Heart attack and heart failure
• Low heart rate (Bradycardia)
• Infections
• Pregnancy
• Hormones related disorders, and
• Medications

 

Symptoms of hypotension include:

• Feeling tired and weak
• Dizziness
• Fainting spells
• Falls
• Nausea, etc.

 

 

FAQ 

 

1. HOW OFTEN SHOULD BLOOD PRESSURE BE MEASURED 

 

The value of blood pressure changes throughout the day, therefore it is advisable to check at least twice a day.

 

2. WHAT IS THE BEST TIME TO MEASURE BLOOD PRESSURE?

 

Blood pressure is best taken in the morning before eating, taking coffee or any medication, and in the evening.

 

Do not measure your blood pressure right after waking up, it is advisable to give an interval of about half an hour after waking up before checking your blood pressure.

 

3. WHAT IS THE PROPER POSITIONING FOR ACCURATE READING?

 

Accurate reading of blood pressure is best achieved in a sitting position with the back supported, feet laid flat on the floor and the arm placed on top of a table with the palm facing upward.

 

Summary

 

Blood pressure is the force exerted by circulating blood on the walls of the arteries. Blood pressure can be high, low or normal. High blood pressure ranges from 90 -120 (systolic) and 60 - 80 (diastolic). Any value recorded to be higher or lower than the normal values indicates signs of high and low blood pressure respectively. 

 

The digital sphygmomanometer is an instrument used for measuring blood pressure and it is considered to be the best for checking blood pressure at home. 

 

To ensure accurate blood pressure value when checked, you need to be seated with your back well supported, your feet laid flat on the floor, and your arm placed on the table with the palm facing upward. 

 

 

 

Sources

 

1. van de Vijver S, Akinyi H, Oti S, Olajide A, Agyemang C, Aboderin I, Kyobutungi C. Status report on hypertension in Africa – Consultative review for the 6^th session of the African Union Conference of Ministers of Health on NCDs. Pan Afr Med J. 2013 Oct 5;16:38. doi:10.11604/paj.2013.16.38.3100.

2. Kleinert HD, Harshfield GA, Pickering TG, Devereux RB, Sullivan PA, Marion RM, Mallory WK, Laragh JH. What is the value of home blood pressure measurement in patients with mild hypertension? Hypertension. 1984. Jul-Aug; 6(4):574-8. [Abstract].

3. Asayama K, Ohkubo T, Hoshide S, et al. From mercury sphygmomanometer to electric device on blood pressure measurement: Correspondence of Minamata Convention on Mercury. Hyperten Res 2016. 39, 179-182. doi: 10 /1038/hr.2015.158

4. NHS. What is blood pressure? Last reviewed Dec. 12, 2022. Accessed April 18, 2023.

5. Healthline. What is the best time of day to take your blood pressure? Last updated March 2,022. Accessed April 18, 2023.

6. Mayo Clinic. Get the most out of home blood pressure monitoring. Last updated. July 8, 2022. Accessed April 18, 2023.

 

 

Related: Hypertension in Nigerian Adults: Essential things to know.

 

 

Published: April 28, 2023

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