How to Use a Sphygmomanometer the Correct Way

For sufferers of white coat hypertension — a syndrome describing the anxiety that some feel when approached by a medical professional — knowing how to use a sphygmomanometer to properly check blood pressure can mean the difference between life and death.

That’s no exaggeration.

High blood pressure is what us folks in the medical business call “the silent killer.” Over many years of living with hypertension, pressure on arterial walls can lead to a number of health challenges including heart disease, and possibly an early death.

Many sufferers live with the pressure for years without symptoms.

For those who live with anxiety and hypertension, managing the anxiety is about as important as managing blood pressure. Visits to the doctor may not be enough, especially if those visits only crank up your anxiety and blood pressure.

The good news for anyone who’s recently learned they suffer from high blood pressure is, measuring blood pressure is about as complicated as making popcorn in the microwave… well, almost that easy.

There are a few variables to consider when embarking on a plan to measure at home.

• Should I go digital or use more traditional methods of measurement?
• What do I need to buy?
• What data am I measuring?
• How should I interpret my results?

By the end of this blog, complete with step-by-step instructions and a video [at the end], you’ll have everything you need to feel confident you can use a sphygmomanometer to test your own blood pressure.

But, first, what is a sphygmomanometer?

What's a Sphygmomanometer?

You know that inflatable cuff they wrap around your upper arm at the doctor’s office, the one the nurse inflates until it feels numb? That’s one part of a sphygmomanometer.

There’s also rubber bulb, the lemon-sized hand pump situated at the end of one tube. Squeezing that bulb inflates the cuff. There will also be a pressure gauge of some sort, manual or digital.

A complete set-up will include a stethoscope, and, of course, someone to read the data. That someone could be you so long as you know what you’re doing.

Don’t worry. It’s not like operating a tattoo gun. There’s very little chance of doing permanent damage, but if your wellbeing is at stake, it’d be good to get it right as soon as possible.

How Does a Sphygmomanometer Work?

Sphygmomanometers are pretty useful tools used to measure blood pressure. We all know that as the heart beats, it pumps blood around the body, and the pressure of your blood is an important metric in all kinds of medical check ups. Checking your blood flow, systolic pressure, and diastolic pressure are highly important to your health. 

Blood pressure cuffs are wrapped around the circumference of the upper arm, targeting the brachial artery, and inflated to well above the expected systolic pressure of the patient—they are then allowed to deflate. 

Once the cuff pressure matches that of the arterial pressure, blood begins to flow past the cuff, creating audible noise called Korotkoff sounds. These are monitored using a stethoscope, and will continue until the cuff pressure falls below the diastolic blood pressure of the patient. 

Blood pressure measurements are documented as "systolic over diastolic". An example may be 120 (systolic) over 70 (diastolic).

 

What's Better—Digital or Manual Sphygmomanometers?

There are several types of blood pressure monitors on the market, from  clinical wall-mount systems to much simpler wrist monitors, with everything in-between.

The simplest among them produce digital blood pressure readings, not much different to use than reading a digital watch versus reading a traditional clock or a mercurial thermometer.

Omron HEM7130, which features a digital display, is a good example, removing the need for a stethoscope and helping to avoid inaccurate readings. 

 

It’s a plug-and-play, portable design, packed with features like storage, body movement detection, and an irregular heartbeat detector. Use is as easy as putting it on, turning it on, and reading the results. I’ll come back to that part in a second.

The Reister Big Ben floor model, also known as an aneroid monitor, is closer to what most folks think of when it comes to sphygmomanometers. Units like the Big Ben feature a clock-face style display, but with one hand instead of two,

Reading a manual scale versus a digital one takes a little more practice to get an accurate reading, but for tracking trends, an exact reading isn’t super necessary. The Reister sphygmomanometers feature auto-balancing making accurate readings easier.

Between the two extreme examples mentioned so far, there are steps in between. Neither is better or worse. A good indicator of which will work better for you is to consider your favourite wristwatch or wall clock.

If you don’t mind changing batteries, then go digital. If antiquity is your style, check out the dial-based sphygmomanometers.

 

What Exactly Do I Need to Get Started?

Depending on which model you choose, you may not need to buy anything more, as is the case with the Omron model. If the dial-based sphygmomanometer is more your style, plan to pick-up a good stethoscope too.

As you’ll learn in the next section, you’ll have to measure heart rate as part of the process. You could purchase the cuff, bulb, air-tubes, and dial separately from the stethoscope or you may consider a nursing student kit like the ACU Student Pack.

One thing is for sure, you won’t need a high-end stethoscope like the cardiology stethoscope unless you’re moonlighting as a heart specialist in your free time.

An entry level or classic stethoscope will do.

Do consider a paediatric version if you’ll be setting up to track a child’s blood pressure. That goes for your blood pressure set-up too. Most ship with multiple sizes of cuffs, the only real variable outside of the stethoscope.

 

How do I Interpret Data from a Sphygmomanometer?

This is the most straight-forward part of the process, but that doesn’t mean it’s easy. There may be concerning results, making subsequent tests challenging.

Since you can stop worrying as easily as you can stop a train, instead redirect the train of your thoughts to something procedural. Do something like make a grocery list in your head.

Although opinions vary somewhat, in general, a normal test will read 120/80 (systolic/ diastolic).

Readings between 120 and 139 for systolic and 80 to 89 in diastolic indicate possible prehypertension.

If your systolic is between 140 and 150, and your diastolic is between 90 and 99, you may have stage I hypertension.

Stage II hypertension is when your systolic exceeds 160, with a diastolic over 100.

Stage III hypertension is over 180 systolic, and a 110 diastolic or higher.

There are many factors that can give you a false reading. Unless it's 180/110, try not to panic over one high reading. Even then, perform at least one retest.

If you’ve been engaged in a robust activity, like working out or playing sports, it may be higher. If you’ve been eating salty food, consuming stimulants (coffee, ADD medication), it will be higher than normal.

Adjust the cuff and take another reading.

If you wait a few hours and it doesn’t come down from a one-off, you may feel more comfortable after contacting a medical professional.

Low readings may mean you need to retest, but if they’re accurate, you should only worry if your physician has advised you to do so or if you feel lightheaded. If you’re concerned in any event, don’t be silly. Contact your physician.

If you’d like to find out more about sphygmomanometers or explore rest of our equipment, take a look around the Medshop New Zealand store or get in touch with a member of our team today.