Many people who have their blood pressure tested face being misdiagnosed, new research has found.
Something as simple as having your arm is in the wrong position when a reading is taken can massively impact the results, the Independent reports. High blood pressure can be hugely dangerous, as it means your heart has to work harder to pump blood around your body.
It’s also a fairly common condition to have, as according to Blood Pressure UK, around one in three adults suffer from it – which is also known as hypertension.
Symptoms of high blood pressure include dizziness, shortness of breath, blurred vision and headaches. However, even more worryingly, sometimes high blood pressure doesn’t actually create any noticeable symptoms. That’s why it’s also sometimes caused a “silent killer“, so accurate testing is vital.
Scientists at at Johns Hopkins Medicine in the US checked the results of blood pressure test patients, noting whether their arms were placed on a desk, supported in their lap, or unsupported and hung at their side when the test took place.
The researchers discovered some startling findings: some arm positions – for example resting your arm on your lap – can significantly overestimate blood pressure readings.
John Hopkins Medicine recruited 133 adults who ranged from age 18 to 80 for the study. Everyone who was tested wore an upper arm blood pressure cuff and had a series of measurements taken with a digital blood pressure device 30 seconds apart.
The study, published in the journal JAMA Internal Medicine, found that putting an arm on your lap overestimated systolic pressure (the top number in a blood pressure reading) by 3.9mmHg and diastolic blood pressure — the bottom number – by 4mmHg.
Being a “dangler”, and letting your arm flop down by your side, also caused systolic pressure to be overestimated by 6.5mmHg and diastolic by 4.4 mmHg.
To get an accurate blood pressure test result, the NHS makes it clear that you should sit on an upright chair with a back with both of your feet flat on the floor, and your arm resting on a table or desk.
Also, to be extra careful, patients should also rest for five minutes before taking a reading and then the doctor should also take another reading several minutes later to check it is accurate.
Dr Tammy Brady, from the Johns Hopkins University School of Medicine, said arm position makes a “huge difference” when it comes to an accurate blood pressure measurement and people should always have their arm on firm support such as a desk or table.
The results suggested people could end up having high blood pressure readings simply based on the position of their arm, with an arm hanging by the side offering the highest readings.
So if you’ve ever had a blood pressure test done in this way, you should get it repeated using the correct position in order to check you haven’t been misdiagnosed.
The NHS says that normal blood pressure is between 90/60mmHg and 120/80mmHg, and high blood pressure is considered to be 135/85 or higher if the reading was taken at home, or 140/90mmHg or higher if the reading was taken at a pharmacy, GP surgery or clinic.
High blood pressure, also known as hypertension, can lead to an array of potentially deadly health conditions and complications, including heart disease, eye problems, angina, kidney problems, vascular dementia and strokes, so it’s important to keep a very close eye on it.
Don’t miss the latest news from around Scotland and beyond – Sign up to our newsletter here.