What Blood Pressure Measures — Two Numbers, and an Answer That Changes With Where You Measure

The Band Wrapped Around the Arm

In 1896, the Italian physician Scipione Riva-Rocci presented a device made of three parts: an inflatable band, a column of mercury contained in a glass tube, and a stethoscope (PMID 39473675).

Earlier in the 1800s, it was first confirmed that inserting a tube into an artery made it possible to measure the pressure inside (PMID 38556854). Riva-Rocci's band was the first method to obtain that value accurately without piercing the body. Thanks to it, a measurement that had been inaccurate and required inserting a tube into the body became a reliable routine in medical practice (PMID 39473675).

The unit mmHg that follows blood pressure numbers also comes from that mercury column. It indicates how many millimeters high the mercury column was pushed up.

The band inflates, it feels tight for a moment, the air releases, and two numbers appear. What those two numbers are the measurements of is usually not explained to anyone. This article looks at four things in turn. What the two numbers measure, what determines those values, why the same person's values change depending on where they are measured, and what "high" means. Unfamiliar terms are explained right where they appear.

The Two Numbers Are Two Moments in a Single Beat

Blood leaving the heart travels through tubes called arteries. Blood pressure is the force with which the blood sent out by the heart pushes against the inside walls of the arteries. It is like the inside walls of a water-filled pipe being pushed outward. Measuring this value is one of the most fundamental tasks when seeing a patient (PMID 30305136).

The two numbers come from within a single heartbeat. With each beat, the two lower chambers of the heart, the ventricles, squeeze and send out blood, and then relax and fill with blood again. Systolic blood pressure is the highest pressure in the arteries while the ventricles squeeze and blood is pushed out. Diastolic blood pressure is the lowest pressure remaining in the arteries while the ventricles refill. When recording blood pressure, the upper number is the systolic blood pressure, and the lower number is the diastolic blood pressure.

The cuff finds these peaks and troughs using sound. When the cuff inflates, the artery in the arm is pressed shut. As air is slowly released until the pressure of the cuff drops below the highest pressure inside the artery, blood forces its way through the squeezed gap every time the pulse reaches its peak, and sounds begin to be heard through the stethoscope.

Releasing it further until the cuff's pressure drops below the lowest pressure inside the artery, blood flows without blockage and the sounds disappear. The point where the sound is first heard is the upper number, and the point where it disappears is the lower number. Today, these two points remain the standard for determining the two values (PMID 28940503, PMID 15699287).

The difference between the two numbers also has a name. Pulse pressure is the value obtained by subtracting the diastolic blood pressure from the systolic blood pressure, in other words, the magnitude of the pressure rise and fall within a single heartbeat. When the top number goes up or the bottom number goes down, the pulse pressure becomes larger.

Even while the heart rests, the pressure inside the arteries does not drop to zero. This is because the large arteries act as a buffer. When the ventricles squeeze out blood, the large arteries expand and hold some of that blood, and while the ventricles rest, they recoil and push the held blood forward. When young, this buffering meshes well with the heart, sending a steady flow all the way to the small blood vessels at the ends of the body (PMID 18048471).

The two numbers are the peak and trough of a single heartbeat, and the width between the two is the pulse pressure.

The Three Things That Set That Number

Three things set the pressure in your arteries: the amount of blood the heart pumps into the arteries, the elasticity of the artery walls, and the speed at which blood drains out of the arteries (PMID 30305136). In terms of a water pipe, it is how much water flows in, how much the pipe stretches, and how fast the water drains out.

Among these three, the one that changes the most as we age is the middle one: the elasticity of the pipe. Arterial stiffness means that the large arteries no longer stretch as much as they used to and become rigid. A new rubber hose swells and bounces back when water rushes in, but an old hose does not swell and instead passes that force straight through.

The main reason large arteries stiffen is that the elastic fibers inside the wall wear out and break. When that happens, the burden the wall used to carry shifts to collagen, a tough fiber that does not stretch as easily (PMID 18048471).

In stiffened arteries, the top number goes up and the pulse pressure gets larger (PMID 38037153). A pipe that cannot stretch cannot hold the blood squeezed out by the heart ventricle, so the peak pressure shoots straight up, and because there is less blood to push back during the resting phase, the bottom drops down as well.

In people over 50 with high blood pressure, the most common pattern is high systolic blood pressure alone, and the rise in blood pressure that comes with age is generally linked to the stiffening of large arteries (PMID 17308214). The measurement that most strongly predicts risk in older adults is also pulse pressure (PMID 17308214). For older people, a wider gap between the two numbers means a signal of danger.

There is also a vicious cycle where stiff arteries raise the systolic pressure, and that elevated pressure stiffens the arteries further (PMID 38037153). However, the expectation that reducing arterial stiffness will provide benefits beyond those gained by simply lowering blood pressure has not yet been proven (PMID 33793325, PMID 38037153).

A low bottom number is not always good news. If the swings between high and low pressure become too extreme, the diastolic pressure drops, and this pressure is needed to supply blood to the heart itself (PMID 33793325). This is because the blood vessels supplying the heart muscle receive blood mainly while the heart relaxes and rests.

The things that set the values are the volume coming in, the elasticity of the pipe, and the speed of drainage, and as we age, the pipe stiffens, making the top number and the gap larger.

The Value Does Not Sit Still

When you go outside on a cold day, your blood pressure rises. It goes up when you climb to a high altitude, when you are next to a loud noise, and when you are exposed to air pollutants. A short exposure merely pushes the pressure up for a moment, but a long-lasting exposure can lead to blood pressure hardening in a high state (PMID 28411895).

A European hypertension society, in a 2023 consensus statement, describes blood pressure as a value that constantly shakes as the environment, behavior, and regulation inside the body interlock (PMID 36723481).

There are also devices in the body that narrow this shaking. The baroreceptor reflex is a feedback mechanism in which sensors in the blood vessel walls read changes in pressure and send commands to the heart and blood vessels, returning blood pressure within a narrow range. When you experience stress, your body reacts and blood pressure rises, and this device suppresses that reaction while allowing each organ to receive as much blood as it needs, holding blood pressure within a narrow range (PMID 35086020). If such a reaction ends quickly, it is an appropriate response for the body, but if an excessively large reaction is repeated, it can be harmful in the long run (PMID 35086020).

There is also a rhythm within the day. Nocturnal dipping is the drop in blood pressure during sleep compared to the daytime. People with a small drop in that range are called non-dippers. Average blood pressure during the night is the value that most sensitively predicts the occurrence of cardiovascular disease and death. A small nocturnal dipping is associated with a poor prognosis—meaning a bad future course—regardless of the overall blood pressure level of the day (PMID 22378470).

There are at least two ways to read this result. A high nighttime blood pressure may be a risk factor in itself, or it may be a sign that some other pre-existing disease has raised the nighttime blood pressure (PMID 22378470). Indices like nocturnal dipping do not easily yield the same result when the same person is measured again, and their definitions also vary widely across literature (PMID 29789641).

The fact that the value differs every time it is measured also has a name. Blood pressure variability is a value indicating how jagged the blood pressure of the same person is every time it is measured. A large fluctuation of the top number measured at each clinic visit over a long period—that is, a high long-term variability in systolic blood pressure—was associated with about a 15% higher risk of death from any cause (PMID 27511067).

This is the result of a 2016 systematic review—meaning a study that comprehensively gathered and organized related research using a set method—that pooled 41 papers. The hazard ratio dividing the risk of the two sides was 1.15, and the 95% confidence interval, which is the range likely to contain the true value, was 1.09 to 1.22. This association appeared independently of the effect of average blood pressure (PMID 27511067).

However, the same review notes that 23 out of 46 analyses were excluded from the main analysis because of a high risk of confounding (PMID 27511067). Confounding is when a factor other than variability creates the apparent association instead. Guidelines have thus far treated blood pressure variability only as a research topic. This is because there are multiple gaps in the evidence, and they have relied on disparate studies with unstandardized measurement methods (PMID 36723481).

Blood pressure is a value that shakes according to the weather, the body, and the time of day, and how to read that shaking is still being refined.

Where You Measure Changes the Answer

When your blood pressure is measured in a clinic, there is usually one more person in the room. Values measured by hand in clinical settings are generally higher than values measured according to standard procedures in studies. One reason frequently cited is the simple fact that a clinic staff member is present. When someone is nearby, people feel tense and tend to converse (PMID 29625508).

That is why different names are attached to different measurement settings. Office blood pressure is the blood pressure measured by medical staff in a hospital or clinic. Home blood pressure is the blood pressure you measure yourself at home with your own device. It is a value obtained over multiple days, ideally under conditions close to everyday life. 24-hour ambulatory blood pressure is blood pressure measured automatically throughout the day and night by wearing a device on your body during daily life and while sleeping (PMID 17345981). An American Heart Association advisory states that there is growing recognition that values measured in the office do not match well with values measured in other settings (PMID 15699287).

High blood pressure is a sustained state of elevated blood pressure, and guidelines draw the line at which a value is considered high. That line varies by country, medical society, and year. Diagnosis is still based on office blood pressure, but confirmation using out-of-office measurements—that is, values measured at home or with a device worn on the body—is strongly recommended (PMID 34019821).

The reason confirmation is necessary becomes clear when you place two sets of numbers side by side. If you divide people by whether their office number and out-of-office number are high or not, four boxes emerge. If neither is high, it is normal, and if both are high, it is sustained hypertension. The remaining two boxes are cases where the two numbers tell different stories, and you must use both office and out-of-office values together to identify these two boxes (PMID 29789641).

White-coat hypertension is when the value measured in the clinic is high, but the value measured outside the clinic is not high. The name means that blood pressure goes up only in front of a doctor's white coat. Among people whose office blood pressure comes out high and who are not yet treated, 15 to 30% fall into this category, and it is especially frequent in older adults (PMID 25167744).

People with white-coat hypertension had more cardiovascular disease events and deaths than people with normal blood pressure, but overall mortality and stroke risk were not clearly different. This is the result of a meta-analysis that pooled and recalculated the results of multiple studies (14 studies, 29,100 people, average 8 years of follow-up). The authors' conclusion is that the cardiovascular risk may be slightly higher than normal blood pressure, but falls far short of sustained hypertension (PMID 26734955). In terms of risk, it means they sit somewhere between normal and sustained hypertension (PMID 25167744).

It also differs depending on whether or not people take medication. In people not taking blood pressure medications, white-coat hypertension was associated with a 38% increase in cardiovascular disease risk and a 20% increase in all-cause mortality risk compared to normal blood pressure. In people already receiving treatment, neither risk was elevated (PMID 28253216). White-coat hypertension also easily progresses to sustained hypertension (PMID 38761349).

Masked hypertension is when the value measured in the clinic is not high, but the value measured outside the clinic is high. It is the side that gets hidden as if wearing a mask in the clinic. How common it is depends on the denominator. According to a 2020 systematic review, it is 10% when the entire surveyed population is the denominator, and 28% when the denominator is limited to people with normal office blood pressure (PMID 31477513).

The same review grouped masked hypertension together with cases where out-of-office blood pressure remains uncontrolled despite treatment, and calculated the risk for that combination. That combination was associated with a 2.09-fold higher risk of heart and cerebrovascular events, which was comparable to the 2.26-fold risk of sustained hypertension. This means that even if the office numbers are not high, the risk of this group is similar to that of sustained hypertension. However, evidence on how to manage this group was meager (PMID 31477513).

A single office number alone cannot distinguish which of the four boxes a person falls into. The two mismatched boxes can only be seen by measuring outside the clinic.

Errors are also common in the act of measurement itself. Inaccurate values can lead to misdiagnosis and inappropriate treatment (PMID 24791186). An American Heart Association advisory lists measurer training, patient posture, and cuff size as all essential, and notes that automated devices must be independently validated (PMID 15699287).

The devices have also changed. The World Health Organization no longer recommends mercury sphygmomanometers and aneroid sphygmomanometers, where a needle rotates around a dial. The method where a device automatically measures multiple times without a person in the room in a clinic is closest to the values measured by wearing a device on the body during waking hours, and its downside is cost (PMID 33420745). Values measured this way are not associated with the white-coat phenomenon of high values occurring only in the clinic (PMID 29625508). This means that when you remove the person from the room, the inflation of office numbers goes away with them.

When you step outside the clinic, the evidence thickens. The higher the percentage of time that 24-hour ambulatory blood pressure stayed within the range suggested by the 2024 European Society of Cardiology guidelines, the fewer deaths and cardiovascular events occurred. Deaths decreased from 21.3 to 16.1 per 1,000 person-years, and cardiovascular events decreased from 20.3 to 11.3. Because this study is based on observed results, it does not go so far as to mean that the time spent within range directly reduced events. Person-years is the total amount of observation obtained by adding up the years each person was watched (PMID 40249369).

These results came from a 2025 individual-participant data meta-analysis that pooled and re-analyzed data from participant after participant (14 population cohorts, 14,230 people, median follow-up duration 10.9 years). In the same study, office blood pressure misclassified the blood pressure control status of most participants when compared to 24-hour measurement (PMID 40249369).

The 24-hour measurement also has weaknesses. It is not widely distributed, and because the cuff inflates at night and disturbs sleep, it may fail to yield true nighttime blood pressure (PMID 32944089). One review summarizes that both office and out-of-office measurements have strengths and weaknesses, so a person's blood pressure should be obtained in multiple settings and evaluated together (PMID 33785904).

Even the same person receives different numbers in different measurement settings, and the two mismatched boxes can only be seen by measuring outside the clinic.

What "High" Means

Among the lines drawn by guidelines, we will look at two here: which value to call hypertension (definition), and to which value below it to lower blood pressure during treatment (target). The 2025 primary care guidelines from Hypertension Canada define hypertension as 130/80 mmHg or higher, and recommend targeting a systolic blood pressure of less than 130 mmHg during treatment (PMID 40419299).

The 2025 guidelines from the American College of Cardiology and the American Heart Association target an in-office blood pressure of less than 130/80 mmHg in adults with confirmed hypertension, and recommend lowering systolic blood pressure further to less than 120 mmHg. A commentary summarizing this content was written by those supporting that target (PMID 40874629). A 2021 review notes that while definitions differ by guideline, the thresholds for starting treatment are relatively similar (PMID 34019821).

We look first at the evidence that lower is better. Intensive treatment that lowers blood pressure to lower targets reduced major cardiovascular events, myocardial infarctions, and strokes. There were no differences between the two groups in all-cause mortality, kidney-related events, or adverse events—in other words, harmful occurrences arising during treatment. These are the results of a 2019 meta-analysis pooling 55,529 participants across 19 clinical trials (PMID 30948822).

In older adults, the results diverge. A Cochrane systematic review updated in 2024 compared a lower target (140/90 mmHg or lower) versus a higher target for 2 to 4 years in hypertensive adults aged 65 years and older (4 clinical trials, 16,732 participants, average age 70.3 years).

In the lower-target group, stroke was reduced (high certainty). Serious cardiovascular adverse events also likely decreased (moderate certainty), and the number of people who stopped the trial due to adverse events did not increase (moderate certainty). The effect on all-cause mortality was uncertain (low certainty) (PMID 39688187). The terms in parentheses are the authors' ratings for the certainty of the evidence.

The authors' conclusions consist of two sentences: that a lower target may be appropriate for the majority of older adults, and that further research is needed because the benefits and risks may differ in people aged 80 and older and in frail individuals (PMID 39688187). Frailty refers to a state in old age where physical strength and resilience have declined significantly.

The caution of that latter sentence appears in other reviews as well. For healthy individuals aged 60 to 80, the evidence is solid that lowering blood pressure below 150/90 mmHg brought benefits, and if well tolerated, it can be lowered further below 140/90 mmHg. On the other hand, for the very old and frail, individualized and careful assessment is crucial, and treatment can backfire (PMID 28776550).

A 2007 review notes that evidence is still lacking regarding very elderly individuals. This group is particularly vulnerable to the side effects of treatment and to the drop in blood pressure itself, meaning that even if the risk of events like stroke decreases, mortality could increase (PMID 17308214).

There is a line at the bottom as well. Hypotension is a state where blood pressure falls below the range necessary to supply blood to organs. The baroreflex we saw earlier keeps blood pressure within a narrow range so that the blood going to organs matches demand (PMID 35086020). Hypotension is the side where blood pressure drops below that range, leaving organs unable to receive as much blood as they need.

There is a single reason why these values are measured so frequently. Hypertension usually comes with no symptoms, which is why measuring blood pressure is the only path to early detection and timely treatment (PMID 38556854). Worldwide, fewer than half of adults with hypertension know their own diagnosis, and among those treated, only one-third have it controlled (PMID 38556854).

Hypertension is the single largest contributor to global disease burden—the health lost to illness and death. Despite being a highly manageable condition, the rates of knowing, treating, and controlling it are all low (PMID 34019821).

"High" is a line drawn by guidelines, lines vary by country and age, and which target suits whom remains a matter of ongoing debate.

Where to Look Further

This is the front porch for reading the two numbers, and there are several doors this article left open as it passed by.

Where these values come from and how the heart pumps out blood are explored from the beginning in How the Heart Moves Blood — Four Chambers, Four Doors, Two Loops. The textbook debate surrounding what determines this flow is also found in that article.

For cerebrovascular disease, whether its symptoms are apparent or not, high blood pressure is a potent risk factor (PMID 22528841). What actually happens when that disease unfolds is covered in What a Stroke Actually Is — Blocked, Burst, and the Clock. Cholesterol, the other line on your health checkup report, continues in What Cholesterol Is and Why We Measure It — Four Lines on a Blood Test, and the Packages They Name.

How numbers getting better and people getting better diverge is handled in Better Numbers, Better Patients? — An Introduction to Surrogate Endpoints. Blood pressure is the textbook example of that question. How to translate sentences like "risk increased by 38%" into the number of actual people is answered in What Does "50% Lower Risk" Mean in People? — Reading Relative Risk, Absolute Risk, and NNT.

The ways that what we eat ties into these numbers are covered in "Coffee and Health — What We Got Wrong, and the Warnings That Still Hold" and "The Mediterranean Diet Paradox — Is Fat the Enemy of the Heart, or Essential to Health?".

What happens when the blood vessels supplying the heart itself are blocked is addressed in What Coronary Artery Disease Is — The Road That Feeds the Heart, Narrowed and Blocked. What changes when the heart's rhythm is disrupted continues in What Atrial Fibrillation Is — The Upper Chambers That Lost the Beat, and the Blood That Pools There.

Source Papers

• "From Concept to Cure: The Life and Legacy of Scipione Riva-Rocci." (2024) — PMID 39473675 — Riva-Rocci invented the mercury sphygmomanometer in 1896. Consisting of an inflatable cuff, a mercury column pressure gauge, and a stethoscope, it transformed inaccurate and invasive measurement into routine, reliable clinical practice.
• "History and evolution of blood pressure measurement." (2024) — PMID 38556854 — Invasive arterial cannula measurement was first shown to be possible in the 1800s. Because high blood pressure usually has no symptoms, measuring blood pressure is the only path to early detection and timely treatment. Less than half of adults worldwide who have hypertension know their diagnosis, and of those treated, only a third have it controlled. Most cuffless new techniques measure relative changes, require regular calibration, and lack adequate existing validation protocols.
• "The meaning of blood pressure." (2018) — PMID 30305136 — Arterial pressure measurement is one of the most fundamental elements of patient care. Arterial pressure is determined by the volume the heart pumps into the arteries, the elastance of the arterial walls, and the rate at which blood leaves the arteries. Arterial pressure is regulated by changes in cardiac output and changes in vascular resistance, and these two regulatory variables can sometimes diverge from each other.
• "Measuring arterial blood pressure in humans: Auscultatory and automatic measurement techniques for human biological field studies." (2018) — PMID 28940503 — Phase 1 and phase 5 of the Korotkoff sounds are the preferred judgment criteria for systolic and diastolic pressure. Measurer training, posture, and cuff size are essential.
• "Recommendations for blood pressure measurement in humans and experimental animals: part 1." (2005) — PMID 15699287 — American Heart Association recommendations. The phase 1 and phase 5 Korotkoff sound auscultation methods are the standard for clinic measurement, and measurer training, patient posture, and cuff size are all essential. Automatic devices must only be those independently validated using a standard protocol. There is a growing awareness that clinic measurements do not align well with measurements in other settings, and home measurement predicts cardiovascular events. 24-hour measurement predicts risk better than clinic measurement and is useful for diagnosing white-coat hypertension.
• "Arterial aging: pathophysiological principles." (2007) — PMID 18048471 — Review mixed with historical article. In the 19th century, clinicians and life insurance companies viewed arterial stiffening as an indicator of vascular aging and cardiovascular risk even in asymptomatic individuals. Aortic stiffening is primarily due to fatigue and fracture of elastin lamellae and the transfer of stress to collagen. The buffering function of elastic arteries (mainly the aorta) creates optimal interaction with the heart in youth and an even flow in the periphery. Aging is better observed through arterial pressure waveform changes than through cuff sphygmomanometers.
• "Blood pressure and ageing." (2007) — PMID 17308214 — Isolated systolic hypertension is the most common type of hypertension in people over 50. Age-related increases in blood pressure are primarily associated with structural changes in the arteries, particularly large artery stiffening. The strongest risk predictor in older adults is pulse pressure, which is enlarged by a falling diastolic and a rising systolic. Treating older patients reduces the risk of cardiovascular events, but evidence for the oldest-old is still lacking, and this group is particularly vulnerable to side effects and blood pressure lowering, which can increase mortality even if stroke risk is reduced.
• "Arterial stiffness and hypertension." (2023) — PMID 38037153 — Stiffened arteries raise systolic blood pressure and pulse pressure, and the elevated systolic pressure further stiffens the arteries, creating a harmful cycle of inflammation and calcification. Further research is needed to determine whether improving arterial stiffness improves the prognosis of hypertensive patients.
• "Arterial Stiffness and Cardiovascular Risk in Hypertension." (2021) — PMID 33793325 — Stiffness increases pulsatile load in the microvessels of the brain and kidneys as well as systolic load on the left ventricle, and excessive pressure pulsatility drops the diastolic pressure needed for coronary perfusion. Reducing stiffness is expected to provide benefits beyond pressure reduction alone, but this hypothesis has not yet been proven.
• "The Environment and Blood Pressure." (2017) — PMID 28411895 — Cold temperatures, high altitude, high noise, and air pollutants noticeably raise arterial blood pressure. Short exposures result in only acute spikes, but chronic exposure can lead to persistent hypertension.
• "Blood pressure variability: methodological aspects, clinical relevance and practical indications for management — a European Society of Hypertension position paper." (2023) — PMID 36723481 — European Society of Hypertension consensus statement. Blood pressure is not a static indicator but constantly fluctuates through the interaction of environmental and behavioral factors and intrinsic cardiovascular regulatory mechanisms. Blood pressure variability was treated only as a research topic in previous guidelines because the evidence for its clinical significance has several gaps and is based on heterogeneous studies with limited measurement standardization.
• "Stress and the baroreflex." (2022) — PMID 35086020 — The baroreceptor reflex buffers the stress response, keeping blood pressure within a narrow range while ensuring long-term perfusion meets demand. Short-term responses are adaptive, but the repetition of exaggerated cardiovascular stress responses can be maladaptive in the long term.
• "Nocturnal blood pressure and cardiovascular disease: a review of recent advances." (2012) — PMID 22378470 — Mean nocturnal blood pressure is the most sensitive predictor of cardiovascular morbidity and mortality, and a small nocturnal drop is associated with a poor prognosis regardless of the 24-hour blood pressure level. However, this can be interpreted in two ways — it may be a risk factor in itself, or a marker of existing and concurrent disease.
• "Diurnal blood pressure changes." (2018) — PMID 29789641 — The definition of diurnal blood pressure changes varies greatly across the literature, causing confusion. The relatively poor reproducibility of diurnal change indicators, including nocturnal dipping, is an underestimated problem.
• "Blood pressure variability and cardiovascular disease: systematic review and meta-analysis." (2016) — PMID 27511067 — 41 papers from 19 observational cohorts and 17 clinical trial cohorts. Increased long-term variability in systolic blood pressure was associated with all-cause mortality (HR 1.15, 1.09–1.22), cardiovascular mortality (1.18, 1.09–1.28), and cardiovascular events (1.18, 1.07–1.30). The magnitude is similar to the association between cholesterol indices and cardiovascular disease. Of 46 analyses, 23 were excluded from the primary analysis due to a high risk of confounding, and future studies must avoid the trap of common confounding.
• "Automated Office Blood Pressure Measurement." (2018) — PMID 29625508 — Manual clinic blood pressure measurements are generally higher than research measurements following standard procedures, with the main reasons being the presence of clinic staff and conversation. Values obtained quietly and multiple times using a fully automatic device (AOBP) are more accurate than manual clinic values, are not associated with the white-coat phenomenon, and are similar to daytime ambulatory blood pressure and home blood pressure.
• "Blood pressure measurement." (2006) — PMID 17345981 — The distinction between clinic measurement, self (home) measurement, and ambulatory blood pressure measurement. Home measurement provides values over multiple days under conditions close to daily life and has no white-coat effect. Ambulatory blood pressure provides 24-hour values and day and night averages.
• "Arterial hypertension." (2021) — PMID 34019821 — Lancet seminar. Hypertension is the largest contributor to the global disease burden, yet control rates are low. Diagnosis still relies on clinic blood pressure, but confirmation with out-of-clinic measurement is strongly recommended. Although the definition of hypertension varies by guideline, the indications for treatment are relatively similar. Despite being a largely manageable condition, recognition, treatment, and control rates are disappointingly low.
• "[White-coat hypertension]." (2014) — PMID 25167744 — White-coat hypertension is defined as a case where clinic blood pressure is high and ambulatory or home blood pressure is normal. It appears in 15 to 30 percent of untreated individuals with high clinic blood pressure and is particularly frequent in older adults. Its prognosis is recognized as intermediate between normal blood pressure and sustained hypertension.
• "White-coat hypertension and cardiovascular events: a meta-analysis." (2016) — PMID 26734955 — 14 studies involving 29,100 people (13,538 normal, 4,806 white-coat, 10,756 sustained, mean age 59, follow-up 8 years). White-coat hypertension had higher cardiovascular morbidity and mortality than normal blood pressure, but all-cause mortality and stroke risk were not significantly different. Conclusion: The risk of white-coat hypertension may be slightly higher than normal blood pressure, but falls well short of the risk of sustained hypertension.
• "White-coat hypertension is a risk factor for cardiovascular diseases and total mortality." (2017) — PMID 28253216 — In untreated cohorts (23 cohorts, 20,445 people), white-coat hypertension was associated with a 38% increase in cardiovascular disease risk and a 20% increase in all-cause mortality compared to normal blood pressure. However, in treated cohorts (11 cohorts, 8,656 people), neither risk was increased.
• "White Coat Hypertension & Cardiovascular Outcomes." (2024) — PMID 38761349 — White-coat hypertension is relatively common, raises cardiovascular risk in a small but clear manner, and easily transitions into sustained hypertension. Results differ between untreated and treated individuals.
• "Masked Hypertension: A Systematic Review." (2020) — PMID 31477513 — ⚠️There are two populations. The prevalence of the masked phenomenon (MHT+MUCH) is 11% overall (9–14) and 32% of the denominator with normal clinic blood pressure (25–40), while masked hypertension (MHT) alone is 10% (9–11) and 28% (15–41). The risk (fatal and nonfatal cardiac and cerebrovascular events 2.09 times [1.80–2.44], comparable to sustained hypertension 2.26 times [1.84–2.78]) is the combined MHT/MUCH value, and the abstract writes was associated with. The diagnostic agreement between home blood pressure and ambulatory blood pressure was 83% by percentage, but kappa was only 0.46. The evidence for managing MHT/MUCH was meager.
• "Strategies to reduce pitfalls in measuring blood pressure." (2014) — PMID 24791186 — Blood pressure measurement errors in clinical practice are common, and inaccurate measurement can lead to misdiagnosis and inappropriate treatment. Automated oscillometric devices are an acceptable alternative if an appropriate cuff size is used, and aneroid devices require frequent calibration.
• "Office blood pressure measurement: A comprehensive review." (2021) — PMID 33420745 — The World Health Organization no longer recommends mercury or aneroid sphygmomanometers. Oscillometric devices are recommended, among which automated office blood pressure measurement devices yield values closest to daytime ambulatory blood pressure. The weakness is the cost barrier.
• "Ambulatory blood pressure monitoring, European guideline targets, and cardiovascular outcomes: an individual patient data meta-analysis." (2025) — PMID 40249369 — 14 population cohorts involving 14,230 individuals, median follow-up of 10.9 years. As the quartile of percentage time in target range (PTTR) over 24 hours increased, mortality decreased from 21.3 to 16.1 cases per 1,000 person-years, and cardiovascular events decreased from 20.3 to 11.3 cases. Clinic blood pressure misclassified most participants regarding blood pressure control status compared to 24-hour PTTR.
• "The Role of Nocturnal Blood Pressure and Sleep Quality in Hypertension Management." (2020) — PMID 32944089 — Nocturnal ambulatory blood pressure is more closely associated with fatal and nonfatal cardiovascular events than daytime ambulatory blood pressure. However, ambulatory blood pressure monitoring has low uptake and can disrupt sleep, failing to yield realistic nocturnal values.
• "In-office and out-of-office blood pressure measurement." (2024) — PMID 33785904 — Both in-office and out-of-office blood pressure measurements have advantages and disadvantages, and individual blood pressure information should be properly obtained and evaluated from multiple aspects. Recent guidelines widely recommend out-of-office measurements.
• "Hypertension Canada guideline for the diagnosis and treatment of hypertension in adults in primary care." (2025) — PMID 40419299 — Canada 2025 Guideline. Sets the unified definition of hypertension at 130/80 mmHg or higher, and targets a systolic blood pressure below 130 mmHg during treatment.
• "Debate on the 2025 Guideline … New Blood Pressure Targets, Lower Is Better—And Possible." (2025) — PMID 40874629 — A commentary written from the 'supporting' side of the debate. The 2025 ACC/AHA guidelines recommend targeting a clinic blood pressure below 130/80 mmHg in adults with confirmed hypertension and lowering systolic blood pressure further to below 120 mmHg. The previous edition stood for 8 years.
• "Optimal blood pressure targets for patients with hypertension: a systematic review and meta-analysis." (2019) — PMID 30948822 — 19 clinical trials involving 55,529 people, mean follow-up 1.6 to 12.2 years. Intensive lowering significantly reduced major cardiovascular events, myocardial infarction, and stroke. However, there was no difference between the two groups in all-cause mortality, renal events, or adverse events.
• "Higher blood pressure targets for hypertension in older adults." (2024) — PMID 39688187 — Cochrane 2024 update. 16,732 people aged 65 and older (4 trials, mean age 70.3 years), 2 to 4 years. The lower target was 140/90 mmHg or less, and the higher target was a systolic of 150 to 160 or a diastolic of 95 to 105 mmHg. The lower target reduced stroke (high certainty) and likely reduced serious cardiovascular adverse events (moderate certainty), while not increasing discontinuations due to adverse events (moderate certainty). The effect on all-cause mortality is uncertain (low certainty). The newly included trial was the first to place a lower bound on the target, comparing systolic 130–150 versus 110–130 mmHg. Author conclusion: That lower target (140/90 mmHg or less) may be appropriate for the majority of older adults, but in those aged 80 and older or frail individuals, benefits and risks may differ, requiring further study.
• "Blood Pressure Targets in the Hypertensive Elderly." (2017) — PMID 28776550 — The evidence that healthy older adults aged 60 to 80 benefit from lowering below 150/90 mmHg is solid, and if well tolerated, it can be lowered below 140/90 mmHg. However, for the oldest-old and frail patients, individualized, cautious assessment is crucial, and treatment can backfire.
• "Nocturnal blood pressure, morning blood pressure surge, and cerebrovascular events." (2012) — PMID 22528841 — Hypertension is a strong risk factor for both symptomatic and asymptomatic cerebrovascular disease. 24-hour blood pressure correlates more closely with cerebrovascular disease than clinic blood pressure does.