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Written by Dr Katie Stephens, GP
Dr Katie graduated from the University of Manchester in 2007 (MBChB) and completed her GP training in the West Midlands in 2012 (MRCGP).
Once you have a machine, one of the most important instructions is to make sure that you sit quietly for at least a minute before taking your blood pressure. Ideally, sitting for 5 minutes is even better. Blood has energy and oxygen in it. As the heart is a dynamic organ, it can change how hard it beats in response to the body’s demands. Even a slow walk around the room increases energy and oxygen use in the muscles of the legs, meaning they need more blood pumping to them compared to when they are at rest.
The heart responds to this by pumping harder (raised blood pressure) and faster (raised heart rate) Sitting still has the opposite effect – the muscles of the body are resting and so don’t need as much blood pumping to them. The heart can relax by beating less hard (lower blood pressure) and slower (lower heart rate).
If you have just been particularly active, or if you’ve smoked a cigarette or had a caffeinated drink, you may need closer to 30 minutes for your heart to ease off to a ‘resting’ level.
How to put a blood pressure cuff on?
Once you are ready, open the instructions that came with your machine. These will vary somewhat depending on whether you are using an upper arm cuff or wrist machine.
However, apart from being mindful of sitting quietly for an appropriate length of time before, the other important steps to follow for both types of machine include:
- Sitting still and quietly throughout the process. Even talking while the cuff inflates increases the body’s need for oxygen and tends to raise the blood pressure. I’ve seen many patients surprised at how much their blood pressure falls when I repeat it while they aren’t talking.
- The cuff of the machine should ideally be worn directly on the skin or potentially through only very thin clothing. Thick sleeves, or sleeves rolled up tightly above the cuff can affect the accuracy.
- Your arm should be supported at the level of your heart (roughly in line with your breastbone).
- Your back should also be supported.
- Both feet should be on the ground (legs uncrossed).
For an upper arm cuff:
- Slide the cuff up your arm so that the bottom edge sits about 2-3cm above your elbow.
- Make sure the cuff is snug – you should only be able to put a maximum of one finger between the cuff and your arm, but it also shouldn’t feel too tight.
- Make sure the tubing is pointing down your arm on your bicep.
- Press start.
- Sit still and quietly throughout the process.
Once you have a reading, write it down and repeat the process after another minute or two of sitting quietly. If the second reading is similar to the first, they are likely to be accurate. If it is much lower, it is likely that the first reading is the inaccurate one. In that case, write the result down and repeat your reading a third time after another minute or two of sitting quietly.
Once you have two readings that are somewhat similar, record them both somewhere safe to refer to later. Or, take an average of them and pop this into our blood pressure tool for instant feedback. If it takes multiple attempts to get two similar readings, it may be that you haven’t quite sat still for long enough before starting the readings. Try next time giving yourself an extra few minutes of being still and quiet before your first reading, and you may get accurate readings sooner.
If you are following the 7 day home blood pressure monitoring plan, then ALL readings should be recorded, including the higher first one.
An important point to note here – if you have an irregular heart rhythm (an example of this is Atrial Fibrillation, or AF), this may cause inaccuracies when using home blood pressure monitors. The most reliable way to get your blood pressure checked in these instances is with one of the manual machines where the practitioner inflates the device by squeezing the pump and listens for your heart beat with a stethoscope on your arm. All of Kinetik’s blood pressure machines come with an irregular heartbeat detection alert to warn you if this may be the case for you.
If the alert shows, and you aren’t already known to have an irregular heartbeat, it is important that you do get this looked at somewhat urgently, as this can be a serious medical condition of its own accord. And, as is always the case, if you also have life-threatening symptoms such as chest pain, shortness of breath, or light-headedness, and the alert is showing, please do seek immediate medical attention at your nearest A&E department.
How to read a blood pressure monitor?
Once you have taken your reading, you may be wondering what the numbers mean. There are usually three different numbers shown on your machine:
- SYS. This is short for ‘systolic’ and is the top blood pressure number (118 in this picture). It shows what the pressure is when your heart squeezes.
- This is short for ‘diastolic’ and is the bottom number (78 in this picture). It shows the pressure when your heart is resting in between beats.
- This isn’t actually part of your blood pressure, but can be a handy number to have for many other reasons. It shows how many times your heart is beating in a minute (70 in this picture).