If you think that your big arm is affecting your blood pressure readings, you’re correct.

The size of your upper arm affects the blood pressure reading.

Does arm size affect only the BP reading or does it also affect actual blood pressure?

“Arm size does affect blood pressure reading — but it really is just the reading and not the blood pressure,” says Susan L. Besser, MD, with Mercy Medical Center, Baltimore; Diplomate, American Board of Obesity Medicine and board certified by the American Board of Family Medicine.

“That is because the fit of the blood pressure cuff around the arm affects the reading,” continues Dr. Besser. “If the cuff is too small, the reading may be artificially elevated.

“Blood pressure cuffs come in multiple sizes, from very tiny for preemies to one large enough to fit around a thigh (or a thigh-size upper arm).”

Unfortunately, in this day and age, it is all too easy for people to put on so much body fat that their upper arm actually does become the same size as a thigh.

Shutterstock/Suzanne Tucker

“Each cuff is marked with the fit range so the user can tell immediately if he or she has picked the proper size cuff (not unlike the proper size clothing — too small is a bad fit,” explains Dr. Besser.

Don’t just hastily grab one of these devices off a shelf at the drug store. Read the package first to see what size it’s meant for. They are not a one-size-fits-all device.

If you’re overweight and have been working on losing excess body fat, this is yet one more reason to be motivated: to get more accurate BP readings, as it is easier to get the right fit for an arm that isn’t huge.

However, what if an arm of size is due to muscle bulk? Certainly, you don’t want to lose the muscle you worked so hard for just so that your arm can fit inside a BP device cuff.

Dr. Besser says, “Whether the large arm is due to fat or muscle really makes no difference to the machine — it’s all about the size.”

The solution to muscle-building athletes is to make sure the cuff they use is the right size so that they’re not mislead into thinking that building muscle elevates blood pressure!

Strength workouts lower resting blood pressure and should be part of an overall cardiovascular health and fitness regimen.

Dr. Besser provides comprehensive family care, treating common and acute primary conditions like diabetes and hypertension. Her ongoing approach allows her the opportunity to provide accurate and critical diagnoses of more complex conditions and disorders.
Lorra Garrick has been covering medical, fitness and cybersecurity topics for many years, having written thousands of articles for print magazines and websites, including as a ghostwriter. She’s also a former ACE-certified personal trainer.