Mastering the Home Reading: Common Mistakes When Measuring Your Blood Pressure
Checking your blood pressure at home can be one of the most useful ways to understand what is really happening with your cardiovascular health. But getting an accurate result involves more than just putting on a cuff and pressing a button.
Dr Krishnaraj Rathod, Consultant Cardiologist at One Heart Clinic, explains that home blood pressure monitoring is often more reliable than a reading taken in a medical setting, provided it is done correctly.
“Home blood pressure measurement is one of the most accurate ways of measuring your blood pressure,” he says. “People often think it is just a case of putting a blood pressure cuff on and taking a reading, but it is a bit more complicated than that.”
More than 4 in 10 adults in the UK don’t know their current blood pressure reading, yet an estimated 4.2 million adults are living with undiagnosed high blood pressure. Despite this, home blood pressure monitoring is accessible and very accurate when carried out correctly.
Below, Dr Rathod explains the most common mistakes people make, how to avoid them, and when a reading should prompt you to seek medical advice.
Why Home Blood Pressure Readings Can Be More Accurate
One of the main reasons home monitoring can be more useful is a phenomenon known as white coat hypertension.
Some people become anxious when they are in a medical setting, which can temporarily raise their blood pressure. As Dr Rathod explains, this can make a single reading taken in a hospital or consultation room less representative of someone’s normal blood pressure.
“People get scared in hospitals. You do not necessarily have a quiet room, five minutes of silence beforehand, or an environment without people walking around or talking to you.”
For this reason, home blood pressure monitoring and 24-hour ambulatory blood pressure monitoring are commonly used to help diagnose and monitor hypertension.
That being said, there are common mistakes that individuals can make when measuring their blood pressure. With this in mind, we have put together a list of things to avoid in order to help you obtain the most accurate readings.
5 Common Mistakes When Measuring Blood Pressure At Home
Mistake 1:
Measuring Your Blood Pressure Without Resting First
One of the most common mistakes is taking a reading immediately after moving around or doing something stimulating. Before measuring your blood pressure, Dr Rathod recommends sitting quietly for around five minutes.
“You should be in a quiet room by yourself,” he says. “Sit for five minutes before doing anything, without talking to anyone.”
During the measurement itself, avoid talking, watching television, reading or doing anything else that could distract or stimulate you.
Mistake 2:
Having Caffeine Too Close To Your Reading
Coffee, tea, energy drinks and other caffeinated drinks can temporarily affect blood pressure.
Dr Rathod recommends avoiding caffeine for at least 30 minutes to an hour beforehand where possible.
If you are measuring first thing in the morning, taking your reading before your first coffee or tea can make it easier to keep the conditions consistent from day to day.
Mistake 3:
Wearing The Cuff Incorrectly
For the most reliable reading, the cuff should ideally sit directly against the skin rather than over clothing.
If this is not possible, clothing underneath the cuff should be very thin, but rolling up your sleeve and placing the cuff directly around your upper arm is preferable.
The arm itself should also be supported: “Your arm should rest on a table, chair or pillow, rather than hanging down by your side or held up in the air,” Dr Rathod explains.
Mistake 4:
Using The Wrong Cuff Size
Blood pressure cuffs are not always one-size-fits-all. A cuff that is too large or too small can affect the accuracy of the result. Dr Rathod recommends checking the size range printed on the cuff and, if necessary, measuring the circumference of your upper arm to make sure you are using the appropriate size.
Mistake 5:
Relying On One Reading
Perhaps the biggest mistake people make is treating a single reading as definitive.
“People take one reading and think, ‘This is normal’ or ‘This is abnormal,’” Dr Rathod says. “It is better to get the average.”
He recommends taking at least two readings each time, around one minute apart. Current guidance may recommend two or sometimes three readings, depending on the circumstances.
The important thing is to look at the pattern across multiple measurements rather than focusing on one number.
How Often Should You Measure Your Blood Pressure?
For someone trying to establish their usual blood pressure, Dr Rathod recommends measuring twice a day, ideally in the morning and evening, over several days.
A typical approach would be:
- Take two readings in the morning
- Take two readings in the evening
- Repeat this for seven days
- Disregard the first day’s readings
- Calculate an average using the remaining readings
Why Ignore Day One?
“The first time you take a reading, you may have a bit of anxiety,” Dr Rathod explains. “More often than not, the first day’s reading may be a little less accurate.”
By taking an average of the remaining days, you can obtain a more accurate picture of your typical blood pressure.
What Is The Best Time Of Day To Check Your Blood Pressure?
Consistency is more important than choosing an exact time. Dr Rathod recommends checking once in the morning and once in the evening.
Morning measurements are ideally taken soon after waking and before having coffee or tea. The second set of readings can be taken later in the day, often before bed.
Taking readings at roughly similar times each day can make it easier to identify patterns.
What Type Of Blood Pressure Monitor Should You Use?
Not every home monitor is equally reliable. Dr Rathod recommends choosing a device that displays a recognised certification and check whether the device has been independently tested for accuracy.
The British & Irish Hypertension Society (BIHS) provides a list of approved blood pressure monitors on its website.
What Blood Pressure Reading Should Concern You?
NICE currently defines the relevant home BP measurement threshold as 135/85 mmHg, compared with 140/90 mmHg for clinic measurement. For treated adults under 80, the home blood pressure measurement treatment target is below 135/85; for adults aged 80+, it is below 145/85.
For an otherwise healthy adult without significant additional conditions such as diabetes or kidney disease, Dr Rathod says blood pressure of around 135/85 mmHg or below is generally the target.
“If you are above 135/85, that is when you should seek advice from a GP or cardiologist,” he says.
The exact threshold that applies to you can vary depending on your age, medical history and other health conditions, so persistent higher readings should be assessed properly rather than interpreted in isolation.
What if my blood pressure is very high?
If you get a very high reading around 180/120 mmHg or higher, sit quietly and repeat the measurement. If it remains very high, seek urgent medical advice. If it is accompanied by symptoms such as chest pain, severe breathlessness, weakness or numbness, confusion, difficulty speaking or sudden visual problems, seek emergency medical help.
Does Blood Pressure Naturally Rise With Age?
Blood pressure does tend to rise as we get older, partly because arteries become less elastic over time. However, that does not mean persistent high blood pressure should be dismissed as a normal part of ageing.
“In 90 to 95% of cases, hypertension is what we call essential or primary hypertension, where we do not know one single cause behind it,” Dr Rathod explains.
Instead, it is usually influenced by a combination of genetic, environmental and lifestyle factors. In around 5 to 10% of cases, there may be an identifiable secondary cause, such as an endocrine or genetic condition.
Why High Blood Pressure Can Be Easy To Miss
One of the most important things to understand about hypertension is that it often causes no obvious symptoms.
“High blood pressure is a silent issue,” Dr Rathod says. “There are millions of people walking around with high blood pressure who just do not know it.”
Unlike a heart attack or stroke, hypertension can remain unnoticed for years. This is why regular checking matters, particularly as you get older or if you have other cardiovascular risk factors.
Know Your Numbers
“Blood pressure management is not only about medication. Diet, salt intake, weight, exercise, alcohol consumption and other lifestyle factors can all influence blood pressure. So, if you find that you have high blood pressure, it doesn’t necessarily mean that you will have to take medicines in order to manage it.”
However, if your readings remain high, the most important next step is to understand why. One Heart Clinic’s Hypertension Diagnostic Package is designed to give you a clear, specialist-led assessment of your blood pressure, cardiovascular risk and any potential underlying causes.
Rather than sitting with uncertainty or relying on occasional one-off readings, you can receive structure testing, expert interpretation and a personalised plan for what to do next.
If you are concerned about high blood pressure or want greater certainty about your readings, you can book the Hypertension Diagnostic Package at One Heart Clinic.
