Quick Answer
- A 2026 analysis of 1.4 million adults who joined a research program in England found that more than a third had high blood pressure. Nearly 6 in 10 of them had never been diagnosed or put on medication. High blood pressure rarely causes symptoms, which is why it's often called a silent condition.
- A separate 2026 trial of 100 healthy adults with normal to high-normal blood pressure found that wall-squat exercise lowered blood pressure. One or two sessions a week held onto part of the drop for four weeks, and three sessions a week worked best.
- The only reliable way to know where you stand is to get your blood pressure checked, even if you feel fine. The American Heart Association's guidelines count 130/80 mmHg or higher as high. If yours is high or you take blood pressure medication, check with your doctor before starting a new exercise routine.
More than a third of 1.4 million adults in England who joined a UK health research program had high blood pressure. Almost six in ten of those had never been diagnosed or started on medication. That's the headline from an Oxford Population Health analysis, and it points to a condition that quietly raises the risk of stroke, heart attack, and early death for years before anyone notices anything wrong.
Here's what the Oxford data show, and how far they stretch. We'll also look at why so many cases slip through, and at a separate trial, published about a week later, that tested isometric exercise in healthy adults.
How Common Is Undiagnosed High Blood Pressure?
Researchers at Oxford Population Health looked at blood pressure measured when 1.4 million adults in England joined Our Future Health, a UK research program, between 2022 and 2025. They counted someone as having hypertension if their reading was 140/90 mmHg or higher, or if they were already taking blood pressure medication. By that measure, 37% had it. Of those, 59% had never been diagnosed and weren't on medication. Among people who were on medication, only about half had their pressure under control.
The pattern tracked closely with age. Hypertension affected 15% of adults aged 18 to 39 and 71% of those 80 and older. After adjusting for age, it was about 50% more common in men than in women (42% versus 29%).
One caution matters here. These are people who chose to enroll in a research program, so they aren't a random sample of the population, and the data come from England rather than the U.S. The numbers are also a one-time snapshot taken at enrollment, not a record of people followed over time. They're a strong warning about how much high blood pressure goes unnoticed. But the exact percentages shouldn't be read as national figures for any country.
Why So Many Cases Go Undiagnosed
High blood pressure has earned the nickname "silent killer" for a reason: it typically causes no symptoms at all, even at levels high enough to damage your heart, blood vessels, and kidneys over time. You can't feel it the way you'd feel a fever or a sprained ankle, which means the only way to catch it is to actually measure it.
Part of the problem is structural. Confirming a diagnosis often takes repeat readings, which can leave people in limbo between appointments. And younger adults rarely get their blood pressure checked at all, so a lot of early-stage hypertension never gets flagged until it's further along. The lead author of the Oxford study said the current approach to detecting and managing high blood pressure isn't working well enough.
When symptoms do appear, they tend to show up only at very high readings, and can include headaches, shortness of breath, or nosebleeds. Waiting for symptoms is a risky way to find out.
How to Lower Blood Pressure
The established lifestyle factors haven't changed: reducing sodium intake, maintaining a healthy weight, limiting alcohol, managing stress, and staying physically active all have decades of evidence behind them. For the weight and metabolic side of that equation, see our guides to sustainable, non-pharmaceutical weight loss, early signs of prediabetes, and high-protein diets, since blood sugar, weight, and blood pressure problems frequently travel together. Chronic stress is also worth a look; our guide to cortisol testing covers how ongoing stress shows up in the body. Sleep matters too: our recent look at REM sleep and disease risk covers a separate 2026 study linking sleep patterns to the risk of dozens of conditions, including heart failure.
A Second Study: Isometric Exercise and Training Frequency
About a week after the Oxford analysis, a separate trial took on a different question. Isometric exercises are the kind where your muscles tense without changing length, like holding a wall squat or a plank, rather than movements like walking or cycling. Earlier research had suggested that isometric training can lower blood pressure more than some other types of exercise, and in some studies by about as much as certain medications. What wasn't clear was how often you need to do it to keep the benefit.
Researchers at Canterbury Christ Church University recruited 100 adults, average age 37, with normal to high-normal blood pressure (a top number between 120 and 140 mmHg). Everyone was healthy and not very active, and no one was taking blood pressure medication. Eighty of them did four weeks of wall squats at home, three times a week. The other 20 made up a no-exercise control group. Each session was four wall-squat holds with two minutes of rest between them, with the knee angle set so each person reached a target heart rate. The 80 exercisers were then split into four groups for another four weeks: training three times a week, twice a week, once a week, or not at all.
After the first four weeks, the exercisers had lower blood pressure than the controls. Their top number (systolic) was about 9.5 mmHg lower, their bottom number (diastolic) was about 5.5 mmHg lower, and their mean arterial pressure, the average pressure in your arteries across a full heartbeat, was about 6.8 mmHg lower.
Four weeks later, the picture split by frequency. People who kept going once or twice a week still had lower systolic and mean arterial pressure than the controls. Their lower diastolic numbers didn't hold. The group that stopped training lost its gains and ended up no different from the controls.
Three sessions a week did best. Systolic pressure in that group was down 13.73 mmHg from the start of the study, compared with 6.95 mmHg for twice a week and 6.56 mmHg for once a week. Once and twice weekly didn't differ significantly from each other.
The authors also noticed that blood pressure in the once- and twice-weekly groups seemed to be drifting back up. Their reading: fewer sessions slow the loss but don't fully stop it. Only the three-times-a-week group held onto measurable improvements in how much blood vessels resist blood flow and in the nervous system's control of blood pressure.
The practical takeaway: something beats nothing, and more beats less. The authors suggest one or two sessions may help hold onto part of the gain during a busy stretch, while three a week is better for keeping the full effect.
What This Study Can't Tell You
This was a well-run trial, but its limits matter, especially if you already have high blood pressure.
It didn't test people with high blood pressure. Participants had normal to high-normal readings, and anyone who was taking or had ever taken blood pressure medication was excluded. So the results can't tell us how well this routine works for people who already have hypertension or are on medication.
The follow-up was short. The maintenance phase lasted only four weeks, and the authors say the field now needs studies that show whether the benefits hold up outside a lab, in everyday life.
It tested wall squats, with intensity set to each person's heart rate. Planks, which often show up in news coverage, weren't part of the trial.
The authors are also careful about cause and effect. Drops in blood vessel and nervous system measures lined up with the loss of the blood pressure benefit, which fits the idea that those changes explain the effect. But as they write, causality can't be confirmed. And participants knew which group they were in, because there's no way to hide whether someone is exercising.
If your blood pressure is high or not well controlled, you take blood pressure medication, or you have a heart condition, talk with your doctor before starting any new exercise routine, isometric exercise included. Holding a position can briefly raise your blood pressure while you do it. No harms were reported among these healthy participants, but that isn't the same as showing it's safe for everyone.
Clinical Evidence at a Glance
| Claim | Evidence Level | What Research Suggests |
|---|---|---|
| Many people with high blood pressure haven't been diagnosed | Cross-sectional analysis of 1.4 million research-program participants in England | 59% of those with hypertension had never been diagnosed or put on medication; about half of those on medication weren't controlled. Participants chose to enroll, so the figures aren't national estimates |
| Wall-squat training lowers blood pressure in healthy adults | Randomized controlled trial (100 adults, average age 37, normal to high-normal blood pressure, no medication) | After 4 weeks, systolic pressure was about 9.5 mmHg lower, diastolic about 5.5 mmHg lower, and mean arterial pressure about 6.8 mmHg lower than in controls |
| One or two sessions a week can hold part of the drop for a short time | Same trial, 4-week maintenance phase | Systolic and mean arterial pressure reductions held; the diastolic reduction did not. Pressure appeared to drift back up |
| Three sessions a week works best | Same trial | Largest systolic drop (13.73 mmHg from the start) and the only group to keep vascular and nervous-system improvements |
| The results apply to people with high blood pressure or on medication | Not tested in this trial | People on blood pressure medication were excluded; separate studies are needed |
The Bottom Line
High blood pressure is common, almost entirely symptom-free, and often missed. A large English analysis suggests many people with it haven't been diagnosed, though those numbers come from people who joined a research program and shouldn't be read as national figures. Getting your pressure checked, whether at a pharmacy, with a home monitor, or at your next appointment, is the only real way to know where you stand.
As for isometric exercise, a new trial in healthy adults with normal to high-normal pressure found that wall squats lowered blood pressure, and that one or two sessions a week held onto part of the drop for four weeks, with three sessions working best. It didn't test people with high blood pressure or those on medication, so it can't say how well the same routine works for them. If that's you, talk with your doctor before you start.
Frequently Asked Questions
What counts as high blood pressure?
Definitions vary a bit. The 2026 England study counted hypertension as a reading of 140/90 mmHg or higher, or taking blood pressure medication. The American Heart Association's guidelines start stage 1 hypertension at 130/80 mmHg.
What are the symptoms of high blood pressure?
Most people with high blood pressure have no symptoms at all, which is why it's often discovered only through routine screening. At very high readings, some people experience headaches, shortness of breath, or nosebleeds.
How can I lower my blood pressure?
Established approaches include reducing sodium intake, maintaining a healthy weight, limiting alcohol, managing stress, and regular physical activity. Early trial evidence suggests isometric exercise such as wall squats may also help healthy adults, but it hasn't been tested in people on blood pressure medication, so ask your doctor first if yours is already high.
Does isometric exercise lower blood pressure?
In a 2026 randomized trial of 100 healthy adults with normal to high-normal blood pressure, four weeks of wall-squat training lowered systolic, diastolic, and mean arterial pressure compared with no exercise. The trial didn't include people with high blood pressure or on medication.
How often should I do isometric exercises for blood pressure?
In that trial, three sessions a week gave the biggest and most lasting drop. One or two sessions a week kept part of the systolic reduction over a four-week follow-up, but not the diastolic one. It was a short trial in healthy adults, so ask your doctor what makes sense for you.
Is isometric exercise safe if I already have high blood pressure?
The trial didn't test that. If your blood pressure is high or not well controlled, you take blood pressure medication, or you have a heart condition, talk with your doctor before starting. Holding a position can briefly raise blood pressure while you do it.
Do the Oxford numbers apply to the U.S.?
Not directly. The data come from adults in England who joined a research program, so they aren't a national estimate for any country. They do show how much high blood pressure can go unnoticed.
Why is high blood pressure called the silent killer?
Because it typically causes no noticeable symptoms, even as it quietly raises the risk of heart attack, stroke, and kidney damage over time. The only way to catch it is through regular blood pressure checks.
References
- Liu W, et al. Hypertension prevalence, detection, treatment and control among 1.4 million adults in England: a cross-sectional analysis from the Our Future Health study in 2022–2025. BMJ Public Health, 2026. DOI: 10.1136/bmjph-2025-004815. View study
- Swift HT, Pedlar C, Coleman DA, Buckley JP, Wiles JD. Isometric exercise training and blood pressure control: exploring the dose-response to training frequency in a randomised controlled trial. BMJ Open Sport & Exercise Medicine, 2026;12(3):e003172. View study
- University of Oxford. Two-thirds of adults with high blood pressure do not know they have it (press release, 23 September 2026). View press release
- Canterbury Christ Church University. New study shows just one workout a week could benefit blood pressure (press release, 2026). View press release
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