These 11 simple mistakes are giving you false high blood pressure readings – doctors confirm
Cuff size is not one-size-fits-all. Imagine trying to use the same cuff on a slender person and a bodybuilder—it simply wouldn’t work. Using a cuff that is too small for your arm will cause it to over-squeeze the artery, leading to a falsely high reading of up to 11 points. Conversely, a cuff that is too large will not provide enough compression and can give you a falsely reassuring low number. The only way to know for sure is to measure the circumference of your upper arm with a flexible tape measure and compare it to the range printed on the cuff itself. When you buy a machine, make sure you are buying one with the correct cuff size for you.
8. You’re Using an Unreliable Monitor
Not all blood pressure machines are created equal. With the rise of online marketplaces, there are many cheap, unvalidated knock-offs out there. More and more people are also using wrist monitors for convenience. While convenient, wrist monitors are highly prone to error. The arteries in the wrist are narrower and not as deep as the one in your upper arm, and even a tiny change in the position of your hand can throw off the reading significantly. For this reason, upper-arm cuffs are strongly recommended unless you are physically unable to use one. To ensure your device is accurate, I always tell my patients to choose a monitor that is listed on ValidateBP.org. This organization uses a rigorous, independent process to test and approve blood pressure monitors for clinical accuracy.
9. You’re Relying Only on In-Clinic Readings
As mentioned earlier, the doctor’s office is often the worst place to get a true blood pressure reading. There are two dangerous phenomena at play. The first is “White Coat Hypertension,” where anxiety about the medical setting causes a temporary spike in blood pressure. This affects up to 20% of people and can inflate a reading by 30 points, potentially leading to a misdiagnosis of hypertension. Even more common and dangerous is “Masked Hypertension.” This affects up to 30% of people and is the opposite situation: your blood pressure is normal at the doctor’s office but high the rest of the time. This is incredibly risky because the problem goes undetected. For both of these reasons, regular home monitoring is the only way to know what’s really going on.
10. You’re Not Measuring Consistently
Your blood pressure fluctuates constantly throughout the day based on stress, activity, sleep, hydration, and more. A single high reading is not a cause for panic, and it’s certainly not a diagnosis. Hypertension is about chronically elevated blood pressure over time, which is what damages your blood vessels and organs. To account for these daily fluctuations and get a true average, you need a consistent measurement schedule. The recommended protocol is to take your blood pressure twice in the morning (right after you wake up and use the restroom, but before coffee or medication) and twice at night (just before bed). Do this for one full week and then average all the values.
11. You’re Only Taking One Reading at a Time
Whenever you sit down to measure, you should always take at least two separate readings. The very first measurement is often slightly higher than the subsequent ones. This can be due to a bit of anticipatory anxiety or simply your body’s initial reaction to the cuff squeezing your arm. By waiting a minute after the first reading and then taking a second one, you allow your body and blood vessels to relax, giving you a more accurate number. You should then record the average of those two readings. This simple habit of taking two readings in the morning and two at night provides a much more stable and reliable dataset.
Conclusion
Getting an accurate blood pressure reading isn’t difficult, but it does demand careful attention to detail. By consciously avoiding these common mistakes, you empower yourself with the correct information about your cardiovascular health. The goal isn’t to chase a single “good” number but to understand your body’s true baseline over time. If you follow these steps and find that your average reading is consistently over 130/80 mmHg, it’s time to have an informed conversation with your doctor. Taking control of your monitoring is the critical first step to taking control of your health.
