Why hypertension thresholds differ by country

The same blood pressure number can be classified as “normal” in France and “abnormal” in the United States. This isn't a scientific inconsistency — it's the result of two different approaches, each with its own arguments, in a debate that remains active within the international medical community.

Two thresholds, one measurement

In France and Europe, hypertension is defined, for home monitoring, starting at 135/85 mmHg. In the United States, guidelines from the American Heart Association and the American College of Cardiology (2017) lowered this threshold to 130/80 mmHg — a difference that may seem small, but which radically changes the share of the population classified as having hypertension, and therefore the number of people subject to medical management.

A threshold that also depends on how you measure

Before even comparing countries, it helps to know that a threshold only makes sense alongside its measurement method. In Europe, hypertension is defined starting at 140/90 mmHg when blood pressure is taken at the doctor's office, but at 135/85 mmHg for home monitoring, and at 130/80 mmHg average over 24 hours with a device worn day and night. The reason is simple: blood pressure is generally a bit lower at home, at rest, than in front of a healthcare provider. This is the “white coat effect.” The threshold is therefore lowered to correspond to the same level of risk. In the United States, the 130/80 mmHg threshold applies both at the office and at home.

What this actually changes

This difference in threshold largely explains why measured hypertension prevalence looks so different between the two countries: about 48% of American adults versus about 31% of French adults. It isn't that Americans have objectively higher blood pressure on average — it's largely that the classification threshold is lower, including more people in the “hypertensive” category, including people who, under the European threshold, would be classified as having normal blood pressure.

Why one country chooses a lower threshold

The argument from American authorities for lowering the threshold rests on data showing that cardiovascular risk starts rising at blood pressure levels previously considered normal — lowering the threshold therefore makes it possible, in theory, to identify and treat people at increased risk earlier, before complications appear. This reasoning draws notably on large clinical trials that showed a benefit from treating hypertension earlier and more intensively, including at levels previously considered acceptable.

Why other countries keep a more traditional threshold

Conversely, European and WHO guidelines have kept a more traditional threshold, partly out of caution over the risk of overtreating too large a share of the population, with the side effects and costs that implies at the scale of a health system. This more conservative approach also accounts for the fact that lowering a diagnostic threshold has major practical implications — more people classified as sick, more prescriptions, and an overall cost to health systems that must be weighed against the expected benefit in terms of reduced cardiovascular complications.

The 3 severity grades, once hypertension is confirmed

Beyond the simple diagnostic threshold, confirmed hypertension is classified into 3 grades of increasing severity, following a classification widely shared in Europe (2023 ESH guidelines):

• Grade 1 (mild): systolic 140-159 and/or diastolic 90-99 mmHg
• Grade 2 (moderate): systolic 160-179 and/or diastolic 100-109 mmHg
• Grade 3 (severe): systolic ≥ 180 and/or diastolic ≥ 110 mmHg — this last grade corresponds to the hypertensive emergency threshold already mentioned on the Hygietest tool

In the United States, the American College of Cardiology classification distinguishes “elevated” blood pressure (120-129/<80, not yet called hypertension), then stage 1 (130-139/80-89) and stage 2 (≥140/90) — a different naming system from the European classification, which doesn't map term-for-term onto the French grades 1/2/3, which is why it matters not to directly compare an American “stage” with a French “grade” without accounting for this difference in systems.

Management that also differs by grade — and by country

In France, management generally follows a gradual escalation: lifestyle measures (reducing salt, physical activity, appropriate diet) are offered first from grade 1 onward, with medication added quickly if the blood pressure target isn't reached — the most recent guidelines actually tend to speed up this escalation, with dual therapy started immediately upon confirmed diagnosis in many cases, rather than waiting for a single medication to fail first. In the United States, stage 1 is generally managed first with lifestyle measures alone, except in people already at high cardiovascular risk (kidney disease, diabetes, high cardiovascular risk under the American equivalent of SCORE2), in whom medication is started immediately even at this early stage — a difference in approach that reflects, as with the thresholds themselves, different trade-offs between the two health systems.

Guidelines that keep evolving

Positions have moved closer together in recent years. In 2024, the European Society of Cardiology (ESC) kept the 140/90 mmHg threshold to define hypertension, but created an intermediate category, “elevated blood pressure,” between 120/70 and 139/89 mmHg. In this zone, treatment may be offered to people with high cardiovascular risk, after a few months of lifestyle measures. It also recommends, for most people being treated, aiming for a systolic pressure between 120 and 129 mmHg if treatment is well tolerated.

In the United States, guidelines published in 2025 by the American Heart Association and the American College of Cardiology kept the 130/80 mmHg threshold. They emphasize earlier treatment and rely on a new cardiovascular risk calculation, called PREVENT, to decide who should be offered medication. The World Health Organization (WHO), for its part, keeps the 140/90 mmHg threshold in its 2021 guidelines, designed to be applicable in every country, including those with limited health resources.

The two approaches therefore agree on the essentials: risk rises progressively from about 120/70 mmHg onward, and the decision to treat depends as much on the person's overall risk as on the number itself.

A scientific debate that's still open

This isn't a definitively settled question: the international medical community continues to debate the most relevant threshold, with solid arguments on each side. This is exactly why the home monitoring tool offered on Hygietest adapts its interpretation based on the country of residence chosen, rather than arbitrarily imposing a single threshold on everyone, faithfully reflecting the diversity of international approaches currently in use.

Other countries, other approaches still

Beyond the France/United States comparison alone, other countries or organizations sometimes adopt additional nuances in their guidelines — some adjusting the threshold by age, others by the presence of other associated cardiovascular risk factors. This diversity of approaches, far from reflecting scientific confusion, instead illustrates the real complexity of the subject: the “right” threshold partly depends on trade-offs between expected benefits and the risk of overtreatment, trade-offs that can legitimately vary depending on each country's health context and public health priorities.

What to remember

Your raw blood pressure number stays the same no matter the country — it's its interpretation, and therefore the decision to consider it “worth watching” or not, that can vary. In every case, high blood pressure deserves to be monitored over time and discussed with a doctor, regardless of the exact threshold used, since the general trend (blood pressure that rises gradually over time) remains a relevant signal whatever classification threshold is applied.

To take your own measurements, take the “Do I have high blood pressure?” test.