There’s a third number hiding in your blood pressure reading — here’s why you shouldn’t panic over it

Take a recent blood pressure reading and subtract the bottom number from the top one — say, 145 minus 80 gives you 65. That figure has a name: pulse pressure. Your blood pressure monitor doesn’t display it directly, but it’s hiding between the two numbers you already have, and different videos online have been citing wildly different thresholds (40, 60), leaving people with perfectly normal blood pressure needlessly worried. (Based on the insights of Dr. Alberto Sanagustín)

What Counts as “Too Much” Difference?

The 2023 European Society of Hypertension guidelines list a pulse pressure of 60 mmHg or more, in people over 60, as one of the criteria for arterial stiffness. That’s a real, specific clinical reference point — but it’s not a universal cutoff for everyone, for three reasons that rarely get mentioned. First, age: that threshold applies to people over 60; in younger people, the gap is naturally smaller, and the same limit doesn’t apply the same way. Second, context: the guideline uses this figure specifically when evaluating people who already have hypertension — it’s not a general classification for the whole population. Third, the word “criterion” itself: a stiffness criterion isn’t a diagnosis, and it isn’t a treatment target either. In fact, no guideline treats this subtraction as something to specifically treat — treatment targets both numbers themselves, not the difference between them.

Different countries’ guidelines actually weigh this figure differently: the 2023 European hypertension guideline cites it as an arterial stiffness criterion, while the more recent 2025 American guideline doesn’t include it as either a criterion or a treatment target at all. Rather than being confusing, this is genuinely reassuring: if the guidelines themselves don’t agree on how much weight to give this number, no single reading should cause alarm on its own. It’s one more piece of context, not a grade on an exam.

Why the Gap Widens With Age

This is the part that’s rarely explained clearly, and it’s what makes everything else make sense. Your two blood pressure numbers don’t age the same way. Systolic pressure (the top number) tends to rise throughout life. Diastolic pressure (the bottom number) rises only until about age 50-60, then plateaus and eventually tends to decline gradually. When one number rises while the other falls, the gap between them widens on its own — which is why the age-60 threshold exists in the first place, not because something suddenly happens at that age, but because that’s when this gap starts telling a more meaningful story.

Here’s why this happens physically: think of a home water pipe system. When you suddenly open a tap, pressure spikes through the pipe. If the pipes have some flexibility, they absorb that spike without incident. If they’re completely rigid, the impact isn’t cushioned and travels through the whole system — plumbers call this “water hammer,” and it’s why old pipes rattle. Something similar happens with the aorta, the large artery leaving the heart directly. When the aorta is flexible, it stretches slightly with each heartbeat, cushioning that surge of blood. Over the years, it accumulates collagen, loses elasticity, and becomes stiffer — cushioning less, so the pressure spike increases and hits harder wherever that blood travels: the brain, kidneys, and heart itself. It’s worth being careful with this comparison, though — an artery isn’t literally a lead pipe and doesn’t calcify overnight; it’s a slow, gradual process happening to some degree in everyone as they age. This widening gap is, to a real extent, a normal part of the circulatory system aging — not a disease, and not something you did wrong.

Does a Wide Gap Mean Stiff Arteries? Not Necessarily

This subtraction isn’t a direct measurement of your arteries — it’s an indirect clue. To actually assess arterial stiffness, there are dedicated tests, like pulse wave velocity, which doctors consider alongside this number, not instead of it.

Here’s why the number alone can also mislead you: imagine two 72-year-olds. The first has 140/80 (a gap of 60); the second has 180/120 (also a gap of 60). Identical gap — but are these two people in the same situation? Not remotely. The second person’s blood pressure is far higher overall, and that matters enormously even though their pulse pressure came out the same. If you ever get a very high reading, don’t focus on the subtraction — repeat the measurement properly, and if confirmed, that needs to be addressed promptly, especially with any warning symptoms. The gap between your two numbers doesn’t replace the two numbers themselves; the European guideline is explicit that pulse pressure adds information to systolic pressure — it doesn’t replace it.

What a Small Gap Means

If your blood pressure is at normal levels and the gap between your two numbers is small, that’s generally not a bad sign — don’t let anyone tell you otherwise. A very narrow gap can occasionally be meaningful in situations where the heart pumps less blood with each beat, but there’s no simple at-home cutoff for detecting this from the subtraction alone — these situations are recognized by symptoms, not by the math. Watch for: unusually pronounced fatigue that doesn’t match your effort level, dizziness or a sense of nearly fainting (especially on standing), or breathlessness with activity that didn’t used to cause it. If you have a small gap and feel fine, it means nothing on its own. If you have these symptoms, mention them regardless of what your pulse pressure happens to be.

A Wide Gap With Normal or Low Blood Pressure

This is where a lot of unnecessary fear circulates online — the idea that low blood pressure with a wide gap is worse than high blood pressure, using examples like “115/55 is worse than 128/88.” This comparison has two problems. First, an arithmetic one: 115 minus 55 is indeed 60 — right at the reference threshold discussed earlier for people over 60. Second, a comparison problem: 128/88 isn’t actually an ideal blood pressure either — the 88 diastolic already falls into what guidelines consider elevated. Calling the first example “worse” just because the subtraction is bigger tells only half the story.

What actually matters: that reference figure of 60 comes specifically from guidance about people already diagnosed with hypertension. A blood pressure of 115/55 isn’t hypertension by any measure, so that criterion doesn’t apply in the context it was written for. What matters more is how much pressure your arteries are actually under — arteries working at 115 systolic bear far less strain than arteries working at 160. If your numbers are normal or low and you feel well, there’s nothing to act on. What is worth watching: if this wide gap is new for you, or comes with new fatigue, dizziness, or breathlessness, mention that to your doctor — not because of the subtraction itself, but because of the change and the symptoms.

If You’re Young With a Wide Gap

This applies especially to people in their 30s and 40s. A young, fit, athletic person may see a wide gap between their two numbers and panic after watching a video like this one. In younger people, a wide gap doesn’t necessarily come from stiff arteries — it can come from two other things. First, a young, trained heart ejects more blood with each beat, and more blood ejected at once raises the top number more. Second, where you measure matters — the pressure wave isn’t identical at the heart’s exit as it is by the time it reaches your arm; it builds like a wave approaching shore, and more elastic arteries actually amplify that wave more. So an arm cuff can exaggerate the true gap at the heart’s exit in a young, elastic-arteried person.

Here’s the complication: a standard arm cuff can’t distinguish this athletic, low-risk pattern from the opposite case — a young person whose arteries have started stiffening prematurely, which is worth catching early. Both scenarios can produce an identical arm reading. Telling them apart isn’t done at home — it requires repeated measurements over time (sometimes a 24-hour monitor), plus a look at other factors: weight, smoking, sodium intake, family history, and in some cases more specific tests measuring the pressure wave directly at the heart’s exit. The message for younger people: if your numbers come back consistently high, that’s worth investigating regardless of the gap between them — the two actual numbers matter more than their difference.

“I’ve Had These Numbers for Years and Feel Fine”

If you’ve had naturally low blood pressure your whole life, always felt fine, and no doctor has ever raised concern about it, a video online — including this one — isn’t a reason to suddenly worry about something you’ve lived with for decades. What’s changed isn’t your body; it’s that someone just taught you how to do a subtraction. That said, this is different from having a wide, sustained gap for years alongside high blood pressure numbers — that’s a different situation, and one worth having on your radar with your doctor. The distinction matters: having something to mention at your next checkup is very different from starting to panic today over a number you’ve been misreading for years.

If You’re on Medication and Your Bottom Number Runs Low

Nothing in this article is a reason to change your medication, dose, timing, or skip a pill — that decision always belongs with your doctor. With that said: for years, it was believed that a low diastolic (bottom) number was inherently dangerous on its own, based on observations that lower diastolic readings correlated with more cardiac problems. More recent guidelines have revisited this, and the conclusion has shifted — this association is real, but it isn’t necessarily cause-and-effect. Stiff arteries independently do two things at once: they lower diastolic pressure and they raise cardiovascular risk. So when you see low diastolic pressure alongside higher risk together, it’s not that one causes the other — both stem from the same root cause, arterial stiffness.

This has a practical consequence: the 2024 European cardiology guideline specifically addresses the case of systolic pressure above 140 with diastolic below 60, stating that if there’s an indication to treat, it should be treated, provided it’s well tolerated. The high number isn’t left untreated purely out of fear the low one will drop further. That said, “if tolerated” isn’t just filler language — significantly lowering blood pressure can have effects unrelated to the heart that matter too, including dizziness on standing, a sense of instability, and in some cases effects on kidney function, more common the more intensively treatment is pushed, and particularly relevant in older adults. This is why adjustment should be guided by how you feel overall, not the number alone — and it explains why it can feel like your doctor is “experimenting” with your medication or dose; they’re not confused, they’re finding the point where your blood pressure is controlled and you feel well, and that point is different for each person.

Why Guidelines Don’t Treat This Gap as a Target

Because you can’t treat a subtraction directly — you can only move the two numbers that make it up, and moving them affects things in both directions. That’s why pulse pressure is useful for assessment, not as something to chase down with treatment.

What Actually Helps Arterial Stiffness

No pill, food, tea, or supplement rejuvenates an artery — treat any claim to the contrary with real skepticism. What does have genuine scientific evidence behind it for supporting arterial health: regular aerobic activity (brisk walking, swimming, cycling, dancing) for about 30 minutes most days; watching sodium intake, which is often where there’s more room to cut back than people realize; maintaining a healthy weight; and getting adequate sleep along with appropriate medical follow-up.

What to Actually Do With Your Number

Track both numbers, the subtraction, the date, and time for about two weeks under consistent conditions (seated, after a few minutes of rest, without having just smoked or had a stressful moment) before your next appointment. Two situations are worth specifically raising with your doctor: if you’re over 60, have high blood pressure, and this gap consistently runs 60 or above — not a single reading, but a sustained pattern; or if you’ve noticed a clear change from your own personal baseline, even if the new number is still technically below 60 or any other reference cited — your own prior numbers are the best comparison point you have.

Frequently Asked Questions

Is a pulse pressure over 60 always a sign of a problem?

Not necessarily. That threshold comes from guidance specifically about people over 60 who already have hypertension — it’s a criterion for the doctor to look more closely, not a diagnosis or an emergency on its own.

I’m young and fit with a wide gap between my numbers — should I be worried?

Not automatically. In young, athletic people, a wide gap often comes from a strong heart ejecting more blood per beat, plus how the pressure wave amplifies by the time it reaches an arm cuff — a low-risk pattern. Distinguishing this from early arterial stiffening requires repeated measurements and other tests, not a single home reading.

My bottom number is low and I’m on blood pressure medication — should I stop it?

No — never change your medication based on this number alone. The 2024 European cardiology guideline specifically supports treating elevated systolic pressure even with a lower diastolic number, provided it’s well tolerated. Any adjustment should be guided by your doctor and how you feel overall.

Is there a supplement or treatment that specifically targets pulse pressure?

No — you can’t treat a subtraction directly, only the two numbers that make it up. Be skeptical of any product claiming to specifically “fix” this number or reverse arterial aging.

Disclaimer: This article is for informational purposes only and does not replace direct medical evaluation. Nothing here is a reason to change, stop, or adjust your blood pressure medication, dose, or timing — always consult your doctor, who knows your full history and can interpret your numbers in your specific context.