Measuring

Morning vs evening blood pressure: why the two readings differ, and what the pair is for

Your monitor can hand you two different numbers on the same day and both can be right. Here’s what makes a morning reading sit apart from an evening one, what the UK guideline actually does with the pair, and the reading a twice-daily routine can miss completely.

NK Medically reviewed by Dr Nouman Kazmi, MBBS FCPS ·8 min read

Key Takeaways

Your blood pressure runs on a daily cycle. The BHF’s page on its TIME trial puts it in one line: it falls when we sleep at night and rises in the morning. Two readings taken twelve hours apart are sampling different parts of that cycle, so a gap between them is the ordinary case and not a fault in the machine.
NICE asks for the pair so that it can be averaged. Recommendation 1.2.7 of guideline NG136 wants two consecutive measurements at each sitting, at least a minute apart and seated, twice daily, ideally morning and evening, for at least four days and ideally seven.
Then it throws the first day away. Everything recorded on day one is discarded and the average of what’s left is the figure that gets used. NICE confirms a diagnosis at a clinic reading of 140/90mmHg or higher together with a home average of 135/85mmHg or higher.
So the gap between your morning number and your evening number isn’t a quantity the home protocol scores. The two times of day are there to spread the sample across the cycle, and the pair collapses into one average before anyone compares it to anything.
The pair can also miss the highest reading of the day. Nearly half of untreated patients with high blood pressure had a sharper afternoon peak in the top number than a morning one, in work reported by Taguchi and Tamura in the Journal of Clinical Hypertension, and that afternoon figure tracked thickening of the heart muscle more closely than the morning figure did.
That finding can’t tell you what happens next, and its authors say so. It was a snapshot rather than a follow-up study, the timing of the second peak moved with race, environment, season and lifestyle, and whether it even repeats in the same person on another day is written up as an open question. It’s a reason to ask your GP about a 24-hour monitor, not a reason to start measuring at four in the afternoon.

In This Article

Why the two numbers aren’t the same number
What the UK protocol asks for, and what it does with the pair
The peak a twice-daily routine can miss
The morning surge, and what’s known about it
Common questions
The bottom line

If your GP or nurse has asked you to measure at home, you’ll have been told to take it twice a day, morning and evening. That’s the wording on the BHF’s measuring page, written by senior cardiac nurse Ruth Goss. NICE recommendation 1.2.7 asks for the same rhythm, over four to seven days. Neither of them tells you why the two readings come back different, or what to make of it when the morning figure lands well above the evening one. That’s this page.

Why the two numbers aren’t the same number

Start with the cycle. The BHF’s page on the TIME trial, a research page and not one of its advice pages, opens with the plain version: our blood pressure naturally follows a daily cycle, falling when we sleep at night and rising in the morning. It adds that someone with high blood pressure might not get that overnight fall at all.

The BHF’s main page on high blood pressure puts it more gently. Your blood pressure naturally goes up and down throughout the day and night, it says, and it’s normal for it to go up while you’re moving about. That page carries the at-home figure of 135/85mmHg, and for anyone over 80 it gives 150/90 when a healthcare professional checks it or 145/85 at home. It was updated on 31 March 2026.

Sitting underneath the cycle is a longer list. Taguchi and Tamura, writing in the Journal of Clinical Hypertension in 2020, name circadian rhythms, physical and mental stress, food intake and smoking among the things that move a reading, which is why the time, the place and the method of a measurement count, for them, as part of the measurement. Twelve hours apart, a reading has moved through most of that list: you’ve eaten, moved, worked, worried, sat down again.

What the two UK advice pages do and don’t cover

The NHS page on high blood pressure tells you a reading comes as two numbers, that 140/90mmHg or higher when a healthcare professional checks it and 135/85mmHg or higher at home count as high, and that you may be asked to use a home monitor for a few days. What it doesn’t do, anywhere on the page, is use the words morning, evening or time of day. The BHF’s page on high blood pressure is more than twice as long and doesn’t use them either. Both pages point you at a home monitor. Neither names an hour.

That leaves a reader holding two numbers and no framework for the distance between them. The guideline does have something written down about the pair. It just isn’t a comparison.

Nearly half

of untreated patients with high blood pressure had a more pronounced afternoon peak in the top number than a morning one. Taguchi and Tamura report it in the Journal of Clinical Hypertension, commenting on a study of peak-guided monitoring by Gong and colleagues in the same issue, and they read it as a case that measuring twice a day can leave the day’s highest figure unmeasured. The study was a snapshot, so it can’t say what that means for anyone’s future, and its authors say that’s the next question.

What the UK protocol asks for, and what it does with the pair

NICE guideline NG136 sets out home monitoring in one recommendation, 1.2.7, and the last line of it changes how the rest reads. For each recording, two consecutive measurements, at least a minute apart, with the person seated. Blood pressure recorded twice daily, ideally in the morning and evening. Recording continued for at least four days, ideally seven. Then: discard the measurements taken on the first day, and use the average value of all the remaining measurements.

Count what that produces. Seven days at two sittings a day at two measurements a sitting is twenty-eight numbers, minus the four from day one, leaving twenty-four. Those twenty-four become one average. The threshold NICE then applies, in recommendation 1.2.8, is a clinic reading of 140/90mmHg or higher alongside a home average of 135/85mmHg or higher.

So the morning and the evening aren’t being set against each other. They’re two sampling points across that daily cycle, and splitting the readings between them is what stops a week of measurement from being a week of mornings. The recommendation names morning and evening exactly once, in the clause that asks for the twice-daily rhythm, and it spends the rest of its words on the average.

Why day one gets thrown away

NG136 discards every measurement from the first day before averaging. A protocol that drops its own opening day isn’t resting on any single reading, and that tells you how much weight one number carries here. If your first morning came back higher than you expected, the guideline has already decided not to count it.

The BHF’s measuring page lands in the same place from the practical end. Take your reading, make a note of it, then repeat the inflation a few minutes later to check the two are similar, and go a third time if they aren’t. If your GP or nurse has asked you to check, you’ll need to take it twice in one day, morning and evening, and then make an appointment to discuss the results with them. The destination is a conversation about a set of readings, with the person who asked for them.

That page is also where the equipment details live, and none of them is about the hour on the clock. Use a cuff that wraps your upper arm if you can, snug enough to slide two fingers underneath, and a wrist one only if you can’t. Pick a device from the British and Irish Hypertension Society’s validated list or the international STRIDE BP list. Get it serviced every two years, because a monitor drifts. Monitors start from around £20 in local pharmacies and larger supermarkets, and the BHF adds that if your doctor has asked you to measure at home, they may be able to lend you a machine.

The peak a twice-daily routine can miss

The NHS’s page, the BHF’s page on high blood pressure and the BHF’s page on measuring at home all stop here. If the morning and the evening are two samples from a curve, something happens in between, and in 2020 two researchers at Yokohama City University put that in the title of a commentary piece: afternoon blood pressure increase on home blood pressure measurement, a forgotten entity?

Taguchi and Tamura were writing about a study by Gong and colleagues in the same issue of the Journal of Clinical Hypertension. That study’s figures reach this page through the commentary, because we haven’t read the study itself. As the commentary reports it, nearly 50% of untreated patients with high blood pressure showed a more pronounced afternoon peak in systolic pressure than they did a morning one, and in those patients the afternoon figure was more strongly associated with thickening of the left ventricle than the morning figure was. That association held even after adjusting for the 24-hour average, which is what lets the commentary say that an adequately controlled 24-hour mean can sit on top of an afternoon rise.

The commentary spells out what it thinks that means for home monitoring. Traditional morning and evening measurement, it says, might class many of these patients as healthy, leave them short of their blood pressure goals, and underestimate their cardiovascular risk, because the pressure goes unmeasured during its afternoon peak.

This isn’t an instruction to add an afternoon reading. Taguchi and Tamura list what the study couldn’t settle, and the list is long. It was cross-sectional, so the link between a late afternoon peak and future cardiovascular risk remained, in their words, to be elucidated. The time of the second peak may vary by race, environment, season and lifestyle, and may also vary within the same patient. Whether an afternoon peak is reproducible enough to be worth chasing with a home cuff at all is written up as the open question, and the answer decides whether it belongs to a home monitor or to a 24-hour one. If the pattern of your readings is worrying you, the next step is your GP, who can arrange monitoring that covers the hours you can’t.

None of which makes the morning and evening pair the wrong measurement. The pair is a sample of a curve that moves, taken at two fixed points in the day, and two points can’t tell you what the line did in between. The guideline’s own answer to a gap that matters is the 24-hour monitor. NG136 reaches for that first, and offers home monitoring as the alternative when someone can’t tolerate it.

The morning surge, and what’s known about it

There’s a term in the research for a morning rise: morning blood pressure surge. It’s worth knowing the phrase. It’s also worth knowing that the research uses it more often than it explains it.

Taguchi and Tamura summarise where that evidence sits. Early morning, they write, is a high-risk period in the day for cardiovascular events including stroke and ischaemic heart disease. Previous studies, they add, have reported that the morning blood pressure surge is associated with subclinical target organ damage, and that the surge is a strong predictor of stroke, coronary artery disease and all-cause mortality in patients with high blood pressure as well as in the general population. Those earlier findings reach this page second-hand, through the commentary rather than the original papers, which we haven’t read.

Then the trail stops. None of the sources on this page defines a morning surge. Taguchi and Tamura name it three times without saying how it’s measured or over what window, and the term appears in none of the three BHF pages cited here, nor on the NHS’s page, nor in the part of NG136 this article quotes. So this page can tell you the phrase exists and what the literature associates it with. It can’t tell you what counts as one, because none of the sources puts a number on it.

Where your readings get interpreted is the appointment, not the kitchen.

The BHF’s TIME page adds the pattern underneath. Someone with high blood pressure might not experience the overnight dip at all, and research has suggested that people without the normal day-to-night variation may be at higher risk of a cardiovascular event even when their blood pressure looks well controlled.

So the answer to why your morning figure runs high arrives in two parts: some of it is the cycle doing what the BHF describes, and the rest is a question the sources hand to a 24-hour monitor and a doctor, not to you. That’s not a reason to stop measuring in the morning. NICE asks for the morning reading precisely because the morning belongs in the sample. It’s a reason to take the week of readings to the appointment and let the person who can arrange 24-hour monitoring decide whether the shape needs looking at.

The same logic covers what to do with a reading you don’t like. NG136 asks for two consecutive measurements a minute apart, and the BHF adds a third if the first two don’t agree. Past the third, the guideline has nothing to say about a fourth, and the week of readings it does ask for is the thing it weighs.

Matter BP Tracker

Two readings a day for a week is a record, if you keep it

NICE wants four to seven days of mornings and evenings, day one discarded, the rest averaged. That’s harder to do on the back of an envelope than it sounds. The Matter BP Tracker keeps each reading with its date and time and whatever you noted beside it, so you turn up to the appointment with the whole week rather than the three you remembered.

Open the BP Tracker → Mornings and evenings·Charted over weeks

Common questions

Why is my blood pressure higher in the morning?

Partly because that’s what the cycle does. The BHF’s page on its TIME trial says our blood pressure naturally falls when we sleep at night and rises in the morning, so a reading taken soon after you get up is catching the rise. You’ll also meet the phrase morning blood pressure surge, and it comes with a gap: Taguchi and Tamura name it three times without defining it, and none of the other sources here uses the term at all, so we can’t tell you what size of rise counts as one. Their summary of the research does say this much. Early morning is a high-risk period for cardiovascular events including stroke and ischaemic heart disease. And the surge itself has been reported as associated with subclinical target organ damage, and as a strong predictor of stroke, coronary artery disease and all-cause mortality, both in patients with high blood pressure and in the general population. If your mornings read consistently high across a week, that’s the week to take to your GP.

Why is my blood pressure higher in the evening?

The same cycle, read from the other end, plus whatever the day put into it. Taguchi and Tamura list circadian rhythms, physical and mental stress, food intake and smoking among the things that move a reading, which is most of a working day. There’s also a research answer specific to the later hours: the commentary reports that nearly 50% of untreated patients with high blood pressure peaked in the afternoon rather than the morning, on the top number. Whether that peak repeats in the same person on a different day is one of the questions the authors flag as unanswered, so an evening figure above your morning one doesn’t tell you much on its own. Both readings go into the week, and it’s the week your GP wants to see.

Which reading should I write down, the morning one or the evening one?

Both, and more than one of each. NICE guideline NG136 asks for two consecutive measurements at every sitting, at least a minute apart and seated, twice daily, ideally morning and evening, for at least four days and ideally seven. It then discards every measurement from the first day and averages all the rest. The BHF’s measuring page adds the practical version: note each reading, repeat it a few minutes later to check the two are similar, and take a third if they aren’t. So there’s no winner to pick between the two times of day. The figure that gets used is the average of the lot.

How big a gap between morning and evening readings is normal?

None of the sources here puts a number on it. The NHS page on high blood pressure gives thresholds of 140/90mmHg at a surgery and 135/85mmHg at home and doesn’t mention a time of day. The BHF’s page on high blood pressure says your blood pressure naturally goes up and down through the day and night and doesn’t name an hour either. NICE doesn’t ask you to work the gap out, because its recommendation averages the readings instead of comparing them. If the spread across your week is large enough to be bothering you, that’s a reasonable thing to raise with your GP or practice nurse, who can put it next to the rest of the picture.

Does it matter what time of day I take my blood pressure tablets?

On the outcomes that matter most, a large UK trial says no. The BHF-funded TIME trial enrolled 21,104 people with diagnosed high blood pressure between 2011 and 2018, randomly assigned them to take their tablets in the morning, between 6am and 10am, or in the evening, between 8pm and midnight, and followed them for an average of five years. Heart attacks, strokes and deaths came out alike: 390 in the morning group against 362 in the evening group. The evening group were slightly less likely to report a fall or feeling faint and more likely to report needing the toilet excessively. Professor Tom MacDonald, the chief investigator, said people with high blood pressure don’t need to change the time they take their tablets, and can pick whichever time suits them and causes them the fewest unwanted effects. It’s still a conversation with whoever prescribes them, not a change to make on your own.

Should I add an afternoon reading?

That’s a question for your GP, and the research it comes from doesn’t settle it either. Taguchi and Tamura devote a whole commentary piece to the afternoon peak and still call its consequences unsettled. The study behind it was cross-sectional, so what a late afternoon peak means for future cardiovascular risk was left open. They also note the timing may vary by race, environment, season and lifestyle, and may vary within the same patient, and they name the reproducibility question as the one that decides whether an afternoon peak belongs to home monitoring at all or to 24-hour monitoring. NG136 already reaches for the 24-hour monitor first and offers home monitoring when someone can’t tolerate it. So the route to an answer about your own curve runs through your GP and not through a third reading at the kitchen table.

The bottom line

Your blood pressure moves on a daily cycle, and the BHF’s TIME page says which way: down while you’re asleep, up in the morning. Food, movement, stress and smoking move it too, on Taguchi and Tamura’s list. Twelve hours and a day’s worth of eating, moving and worrying sit between a morning reading and an evening one, so they come back different, and that’s the system working rather than the monitor failing.

What the guideline does next answers most of the question. NG136 asks for both times of day, four to seven days of them, drops everything from day one, and averages the rest into a single figure that goes up against 135/85mmHg. Nowhere in that does the distance between your two readings get scored. The pair exists to spread the sample, and then it stops being a pair.

There is a real gap in the pair, and it sits in the afternoon. Taguchi and Tamura’s commentary reports that nearly half of untreated patients peaked in the afternoon and not the morning, and that the afternoon figure tracked heart-muscle thickening more closely. Their own list of what that study couldn’t answer is longer than the finding, so it isn’t a protocol change. It’s the case for the 24-hour monitor NICE already reaches for first, and a question your GP can act on.

That leaves the ordinary work, and it’s the same ordinary work as ever. Same arm, same chair, same two times of day, a validated cuff serviced every couple of years, a week of readings behind you when you go. You can’t see the shape of your own curve from two points on it. You can hand someone a week of points and let them see it.

Continue learning

References

National Institute for Health and Care Excellence. Hypertension in adults: diagnosis and management (NG136), Recommendations. Recommendations 1.2.3, 1.2.4, 1.2.7 and 1.2.8 carry the dates [2019], [2019], [2011] and [2019]. Available at: nice.org.uk
NHS. High blood pressure (hypertension). Page last reviewed 19 July 2024, next review due 19 July 2027. Available at: nhs.uk
British Heart Foundation. High blood pressure (hypertension), causes and symptoms. Page updated 31 March 2026, next review 1 March 2029. The copy read for this article runs to 12,000 characters of a 12,450-character page, so the statement above that it names no time of day covers the part that was read and not the last 450 characters. Available at: bhf.org.uk
Goss R. How to measure your blood pressure at home. British Heart Foundation, page updated 21 October 2026. Available at: bhf.org.uk
British Heart Foundation. High blood pressure: TIME. The page carries no date; it gives the trial’s publication as Lancet 2022;400(10361):1417–1425, and quotes chief investigator Professor Tom MacDonald. Available at: bhf.org.uk
Taguchi S, Tamura K. Afternoon blood pressure increase on home blood pressure measurement: A forgotten entity? J Clin Hypertens (Greenwich). 2020 Oct 15;22(12):2202–2203. doi:10.1111/jch.14078. Two pages commenting on a study published “in this issue” of the same journal (Gong S, Xu Y, Ye R, et al. J Clin Hypertens. 2020;22:2192–2201); the capture carries no label of its own. The Gong and colleagues study it discusses, and the earlier morning-surge findings it summarises, reach this article through it and not from the original papers. Available at: pmc.ncbi.nlm.nih.gov

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