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Dr Brad Stanfield - The 120/80 Blood Pressure Target Is Wrong
Understanding Blood Pressure and Its Importance
The gold standard blood pressure of 120 on 80 is probably completely wrong for you. In fact, I'd almost guarantee it.
So, picture these two people in your mind. One is a mid-40-year-old man. His blood pressure is 118 on 76 and he's worried about heart disease that runs in his family. Then the second person is a late 80-year-old woman. She needs to use a walking stick to get around and her blood pressure is 124 on 68 and she's on two blood pressure medications.
Now based on that information alone, what is the crucial difference between those two people in terms of the blood pressure that they should be targeting? Now most people think that it's their age but it's not. It's frailty. Frailty and past medical history. So let me explain and this is crucial for you to understand so that you can significantly lower your heart attack and stroke risk while minimizing any adverse reactions.
Now why do we chase or why is there that mythical 120 on 80 blood pressure? So the general mechanism is that the higher your blood pressure the more strain there is on your blood vessels and over time that can lead to heart attacks and strokes and it's known as the silent killer because you don't tend to feel high blood pressure until something goes pop as in that heart attack or stroke.
Now a quick note before we go on. I'm Brad Stanfield. I'm a family medicine doctor and I make these videos to explain the science of living a long healthy life. But even though I'm a physician, I'm not your physician. So please discuss with your doctor before making any changes to your health plan.
Why Blood Pressure Targets Are Going Down
Now over the years blood pressure targets have generally gone down. Now this is not a conspiracy by big pharma just to sell more drugs. The blood pressure targets have lowered because of trials such as this one in 2015 and it's called the SPRINT study.
So it involved 9,361 people all over the age of 50 years old. Now what they wanted to check was a blood pressure which was standard at the time of 140 compared to an intensive lowering of blood pressure to 120. Now this study was meant to last about 6 years but it was stopped early after just 3 years because what they noticed is a 25% lower risk of a combination of heart attacks, strokes and deaths.
Understanding the SPRINT Study
Now a quick note on relative versus absolute risk because that 25% number sounds huge. In the intensive group they had 1.65% of patients per year that had the major cardiovascular events. So that was the heart attacks, strokes or death versus 2.19% per year in the standard treatment group. So that was the 140 number. That doesn't sound like a huge difference because in plain terms that's only about half a percentage point fewer events per year. But when you average that out or when you extrapolate that out, you know, 10, 20, 30 years, that absolute risk reduction is huge. And that is why we care about lowering blood pressure, because again, most of the time we can lower blood pressure without causing any side effects. But more on that later.
Now if this sounds settled, why isn't the answer that just everyone should be aiming for a blood pressure of lower than 120? Well, let's have a look at who was actually in that SPRINT trial, because what we don't want to do is extrapolate to a different population. If you're not part of that population, then we don't want to extrapolate those results from this SPRINT trial onto you.
In the SPRINT study, there were no diabetics. These people had no history of strokes and they were not frail. So that's the first problem. Thinking back to that woman we mentioned at the start of the video, that late 80-year-old, this study wouldn't apply to that person.
The second is that in the SPRINT study, they measured blood pressure with an automated device when the patient sat alone. A reading typically runs about five or 10 units lower than if you just went to your doctor to get your blood pressure checked. We'll talk about how to measure your blood pressure correctly later in the video. So there are a lot of confounding factors here, and again, we don't want to extrapolate this data.
The ESPRIT Study
So how does this mean that lower is better if we include patients with diabetes or with strokes or who are a bit frail? A 2024 trial answers that exactly. It was called the ESPRIT study and this study again was huge. It was over 10,000 people and it added in diabetics and stroke patients. There we saw a 12% lower risk of a combination of heart attacks, strokes and deaths in the 120 group compared to 140. So it wasn't quite as big a difference compared to the SPRINT study, but it's still significant.
Balancing Blood Pressure
So if aiming for a lower blood pressure keeps winning, even in the fit people, even in the frail people, even in diabetics and stroke survivors, then why on earth would anyone need to aim for a higher blood pressure? Well, you have to imagine it's a tightrope that we're trying to balance here. Yes, if we lower blood pressure, we do lower the risks of heart attacks and strokes, but if we lower it too much, if we cause problems, then when you stand up, you can start to feel dizzy. In the worst case scenario, you can actually fall over and cause other serious adverse events.
For example, this came into sharp focus in 2015 when a trial from the internal medicine journal was published. In frail nursing home residents over the age of 80, those with a systolic blood pressure, the top number, under 130, who were on two or more blood pressure drugs had a, and get this, 78% higher risk of dying over the 2-year period compared to those who had a blood pressure higher than 130.
One of the reasons for this is that when you stand up and you're a bit frail, if your blood pressure is too low, your body isn't going to pump that blood to your brain, so your brain is starved of oxygen and then you can feel faint and fall over. For example, a meta-analysis of 50,000 people found that orthostatic hypotension, where you stand up and your blood pressure isn't quite high enough to push that blood to your brain, carried a 73% higher risk of falling. That's significant, because in these older people, if they fall and break a hip, they have a 20 to 30% chance of dying within one year.
So again, we've got a tightrope that we need to balance, and this is the part that almost everyone gets wrong. This is why I led with it at the start of the video, and many doctors actually get this wrong as well.
Understanding Frailty and Blood Pressure
This is not about age. When the trials looked at their own fittest patients who were over the age of 75, the ones who were sent for that under-120 target still got benefit and they did not fall more than anyone else. So the falls story was never really about age. It's about frailty. It's not about birthdays, it's whether the body has become too frail.
Picture that older woman at the start of the video who needed to use a walking stick to get around. If we're aiming for a blood pressure of lower than 120, we're probably going to cause her to fall, because when she stands up, her blood pressure is going to be too low.
This also extends to frail 50 and 60 year olds. In the clinic, I'll often see patients who haven't had the chance to look after themselves. Even though they're only about mid-50s, they've lost significant amounts of muscle mass. When they're trying to get around, they move slowly. When they get up, you can see they're starting to wobble and losing their balance. That person has become frail even though they're 50 years old, which is why we should not be focusing just on the age number.
I see plenty of people in the clinic who are very fit and are 90 years old. For those people, yes, we could be aiming for a blood pressure of lower than 120. On the flip side, really fit people might want to go even lower, perhaps a target below 115. The reason is that there's no magic safe threshold when it comes to blood pressure. In 2002, across a million adults, cardiovascular death roughly doubled for every 20 points of systolic blood pressure all the way down to 115 over 75. So again, there's no magic safe threshold, and for some people who are super fit, a blood pressure lower than 115 may be the goal.
Determining the Right Blood Pressure Target
So how do you get this balance right, because it is such a tightrope? Before you argue about what your target should be, whether it should be 120 or 130 or even all the way down to 115, here's the uncomfortable truth: most people are going for a measurement that is simply wrong.
When you go into your doctor and get your blood pressure checked, that is often a really incorrect measurement, because generally when you go into the clinic, your blood pressure goes up anyway. Often there's a bit of rush. Bad cuff technique and all of that just wrecks the reading. So rather than relying on one measurement at the doctor's office, a better approach is to measure it at home.
You don't want to exercise or have caffeine within the past 30 minutes. You want to be nicely seated with your back supported and your feet flat, so you don't want to be crossing your legs. You want your arm at about heart height. You don't want it up here, and you don't want it hanging down like this. Make sure the cuff size is correct. Don't talk during the reading. Have an empty bladder, and ideally sit for at least about 5 minutes to really try and relax.
And you do not want to trust one number. What I recommend to my patients in the clinic is to take two readings, ideally one in the morning and one in the evening. Do that for a week. Throw out the first day's readings because they're generally inaccurate, then average the rest. That will give you a far better, more accurate reading than one reading in the doctor's office.
Only once you have that accurate reading can you start to figure out which target you should be aiming for. A quick screen I do with my patients is to ask: do they have any dizziness when they stand up? Can they stand up unaided? Can they easily jump and then balance themselves? Do they have any heart conditions? If they give favorable answers to those questions, then a target below 120 over 80 is probably appropriate. Of course, make sure to discuss this with your doctor first.
If you do feel some dizziness when standing up, and you feel frailty is coming on, then a higher blood pressure of about 130 or even 140, depending on your frailty, might be appropriate. But if you are becoming frail, please don't be disheartened, because there is so much you can do to get your strength back. The best way to do that is exercise, which also helps to lower your blood pressure safely.
Effective Ways to Lower Blood Pressure
There are a couple of exercises that have been shown to have outsized effects on lowering blood pressure. In a recent study that pulled 270 randomized control trials together, aerobic exercise, such as going out for a run, lowered systolic blood pressure by about 4 and a half points, while isometric exercise, such as wall sits, came out on top at about eight points of blood pressure lowering. So even if you're struggling for time, you can do a wall sit in your office or at home.
If you are becoming frail, one of the best exercises I suggest to my patients is to stand up unaided and then slowly sit back down in their chair, doing that as many times as they can, of course making sure they do it safely. That exercise builds up your thigh muscles, your quads, it builds up your glutes, and it can help lower your blood pressure.
The next lever you can pull is diet. Here I suggest to my patients that they increase their potassium intake, so long as their kidneys are okay. I suggest they increase their non-starchy vegetable intake. I'm not talking about increasing potato or corn intake. Ideally what we want is things like broccoli, peas, carrots and corn. You can pair that with foods that have lots of protein and potassium in them, such as chickpeas, lentils and beans. A 2013 trial found that eating more fruits and vegetables lowered systolic blood pressure by about 3 and a half points in people with high readings.
Next, we ideally want to decrease and stop alcohol. In a 2017 study of people who were drinking six or more units per day, cutting back by about half lowered their systolic blood pressure by 5 and a half points.
Next is weight loss. Of course, this comes with diet and exercise. Across 25 randomized control trials, for every kilogram of weight lost, about one point of systolic blood pressure is dropped. So a 5 kg weight loss is worth roughly five points of blood pressure lowering.
Here is where we might need a bit of assistance from the doctor, because just telling patients to eat less and move more often doesn't work. For some people it does, but for many it doesn't, because there are other metabolic issues causing problems. For example, one thing I always screen for in my patients is Cushing's disease, where there's too much cortisol in the blood. We use a salivary cortisol test at night to check for it. There are other secondary causes that raise blood pressure, such as hypothyroidism. Then there's primary aldosteronism, which we check by measuring blood aldosterone-renin ratios. Another is pheochromocytoma, which we check for using plasma free metanephrines. Another often overlooked cause is renal artery stenosis, where the arteries going into the kidneys are narrowed, which can often cause blood pressure to rise. We think of this in people with high blood pressure who are under 40 years of age.
Once all of those secondary causes have been excluded, what I often see in the clinic is that the primary reason for a person's high blood pressure is their weight. Again, telling patients to eat less and move more can sometimes be helpful, but often we need a bit more support. This is what has changed recently: we can now use GLP-1 medications to help patients with their weight loss.
Key Takeaways
Overall, there are four main points I wanted to get across in this video. Don't just adjust the blood pressure target based on age. Ideally, adjust it based on frailty. Measure blood pressure properly, ideally at home. Then pull the levers you can actually control, such as eating well, exercising and sleeping, and treat secondary causes of high blood pressure, such as excess weight, hypothyroidism and others.
I've put the full write-up of this video, including every study I've cited with all of the numbers, over at drstanfield.com, and it's linked in the pinned comment below. If you want bonus videos from me each week, including members-only health reviews where members share their health stories and I walk through what the evidence says for someone in their situation, you can join as a channel member or on Patreon. You get the bonus videos, early access to these videos, priority replies in the comments, and the Discord community where we discuss the latest health research. And make sure to check out the next video.