Cardiology · interpreting 24-hour BP data
Reading an ambulatory blood pressure recording, what the 24-hour data shows and how it changes your treatment.
A guide to interpreting the 24-hour ambulatory blood pressure recording — daytime and night-time averages, dipping patterns, morning surge, white-coat and masked hypertension, and how these change treatment decisions.
Why patients choose us
- 01
Read by a cardiologist
Your 24-hour recording is interpreted by a consultant cardiologist or hypertension-trained GP — not scored by software alone.
- 02
A report you can act on
Averages, dipping status, morning surge — translated into a plain-English plan, not just numbers on a chart.
- 03
Independent, and free
We are paid by no clinic, so the recommendation is impartial and costs you nothing.
Key facts
The numbers that decide how your recording is interpreted.
Six thresholds that translate a stack of readings into a diagnosis and a treatment plan.
-
Definition
Interpretation of the 24-hour BP recording data — averages, patterns, variability.
-
Daytime > 135/85 mmHg
Daytime average above 135/85 mmHg is diagnostic hypertension.
-
Night-time > 120/70 mmHg
Night-time average above 120/70 mmHg is nocturnal hypertension.
-
Non-dipping < 10%
A BP fall of less than 10% overnight is a poor prognostic sign.
-
Morning surge > 55 mmHg
An early-morning rise greater than 55 mmHg raises stroke risk.
-
Reverse dipping
A rise at night suggests obstructive sleep apnoea or autonomic disease.
In short
A good ABPM report is not just averages — dipping and morning surge change the plan.
The problem
An ABPM recording is only as good as who reports it.
The averages are only the start. Dipping status, morning surge and the gap between clinic and ambulatory readings decide the treatment. That interpretation needs a cardiologist or hypertension-trained GP, not the device’s auto-summary.
-
Recording done, no clear plan?
We take the raw data and turn it into a plain-English report you can act on.
-
Suspected white-coat hypertension?
We compare clinic and ambulatory data side-by-side and separate the two.
-
Non-dipping picked up?
We investigate the drivers — sleep apnoea, kidney disease, evening dosing — and route accordingly.
How the data is analysed
From raw recording to written report — what happens, in order.
Seven steps between the monitor coming off and the plan landing in your inbox.
Phase 1 · Download & auto-analysis
Data pipeline, off-stage for you
Phase 2 · Clinician review
Cardiology or GP, overlaid on your history
Phase 3 · Report
Written summary and plan
- 01
Download & auto
24-hour recording downloaded
The monitor’s data is uploaded to the ABPM software — every reading, every timestamp, every artefact.
- 02
Download & auto
Automated analysis by ABPM software
Software computes daytime and night-time averages, dipping percentages and morning surge from a validated dataset.
- 03
Clinician review
Cardiology or GP review
A clinician overlays the numbers with your history — the numbers alone don’t decide treatment.
- 04
Clinician review
Compare with clinic BP
Clinic readings sit next to the 24-hour picture — the gap tells us about white-coat or masked hypertension.
- 05
Clinician review
Assess dipping status
Night-time fall as a percentage of daytime BP: normal dipper, non-dipper, reverse dipper or extreme dipper.
- 06
Report
Assess morning surge
The rise from the lowest sleep BP to the early-morning average — quantified and flagged if excessive.
- 07
Report
Structured written report
A one-page summary: diagnosis, dipping category, morning surge, and a concrete treatment recommendation.
Typical end-to-end from download to written report: 1–3 working days.
What the recording shows
The eight things a clinician looks for in your 24-hour data.
The recording answers a specific set of questions about your blood-pressure biology across a whole day and night — not just what it reads in clinic.
-
Daytime SBP / DBP average
Awake average — the number that defines diagnostic hypertension when > 135/85 mmHg.
-
Night-time SBP / DBP average
Asleep average — nocturnal hypertension when > 120/70 mmHg, an independent stroke risk factor.
-
Dipping status (dipper, non-dipper, reverse)
Night-time fall as a percentage of day: 10–20% normal, < 10% non-dipping, a rise is reverse dipping.
-
Morning surge magnitude
The early-morning rise from lowest sleep BP — > 55 mmHg raises stroke risk materially.
-
White-coat hypertension
Raised in clinic, normal on ABPM — treatment is usually not needed, but follow-up is.
-
Masked hypertension
Normal in clinic, raised on ABPM — often missed, and carries the same risk as sustained hypertension.
-
Circadian rhythm variability
The shape of your 24-hour curve — variability itself is a cardiovascular risk marker.
-
Red flag: sustained > 180/110 mmHg on recording — same-day medical assessment
Do not wait for the report. Contact your GP or attend A&E the same day.
Metrics explained
Every metric on your ABPM report, in plain English.
What each number in the report actually means for your risk and treatment.
-
Daytime SBP / DBP average
Awake average from readings taken every 20–30 minutes during your normal day.
-
Night-time SBP / DBP average
Asleep average — the single most predictive number for cardiovascular events.
-
Dipping percentage
Quantifies the night-time fall — a normal dipper drops BP by 10–20% overnight.
-
Morning surge
The rise from lowest sleep BP into the first waking hours, in mmHg.
-
White-coat effect
The gap between raised clinic BP and normal ambulatory averages.
-
Masked hypertension
Normal clinic BP with raised ambulatory averages — hidden risk uncovered.
-
BP variability
Beat-to-beat and hour-to-hour variability, an independent risk marker.
-
Reverse-dipping pattern
BP rising at night rather than falling — flags OSA or autonomic disease.
How we read it
A clinician-led read, not a software summary.
Six steps that turn a 24-hour recording into a written interpretation and a treatment recommendation.
The read
How every recording is worked through before your report is signed off.
-
24-hour recording downloaded from a validated ABPM device
-
Automated analysis by ABPM software
-
Cardiology or GP review overlaid on your clinical history
-
Comparison with clinic BP to identify white-coat or masked hypertension
-
Assessment of dipping status and morning surge
-
Structured written report you can act on
Red flags on the recording
Patterns that change the plan.
Nine patterns on a 24-hour recording that shift interpretation from routine to urgent, or that redirect treatment to a specialist.
-
Sustained severe hypertension
Averages > 180/110 mmHg on recording need same-day assessment — do not wait for the formal report.
-
Non-dipping pattern with OSA
A flat night-time curve alongside snoring or witnessed apnoeas points to obstructive sleep apnoea.
-
Reverse dipping
BP rising at night is abnormal — a marker of autonomic disease, kidney disease or severe OSA.
-
Very high morning surge
A rise > 55 mmHg from lowest sleep BP raises stroke risk and often warrants evening dosing.
-
Autonomic dysfunction
Wide swings and postural drops suggest autonomic failure — a specialist referral is the next step.
-
Symptomatic hypertension
Headache, visual disturbance or chest pain alongside high readings needs urgent review.
-
Nocturnal hypertension with renal disease
Night-time hypertension in chronic kidney disease is a strong signal for tighter control.
-
Pregnancy hypertension pattern
Loss of the normal dip in pregnancy raises the pre-eclampsia flag — obstetric review.
-
Suspected phaeochromocytoma
Paroxysmal spikes with sweating and palpitations warrant biochemical work-up before treatment.
Reading your report
An ABPM report can look intimidating. It isn’t.
Whatever the finding, the report keeps to the same four parts.
A quiet reminder
The report is written for your doctor, not for you — and that’s normal.
If you would like us to talk you through it before your follow-up, just ask.
- 01 Header
Indication and clinic BP for comparison
Your details, the reason for the recording, and the clinic readings the ambulatory data will be set against.
- 02 Technique
Device, sampling interval and data quality
Which validated monitor was used, how often it read, and the proportion of successful readings.
- 03 Findings
Averages, dipping, morning surge
Daytime and night-time SBP/DBP, dipping percentage, morning surge in mmHg and variability metrics.
- 04 Impression
The conclusion: read this first
Diagnosis, dipping category, morning-surge flag and a concrete treatment recommendation — read this first.
Next steps
How the recording changes your treatment.
Eight routes out of the report, from reassurance to specialist referral.
-
Reassurance
A normal recording — lifestyle advice, and no medication needed.
-
Lifestyle advice
Diet, weight, alcohol, exercise, salt — the levers that move averages before any drug.
-
Antihypertensive per NICE NG136
Where treatment is indicated, drug and dose follow the current NICE algorithm.
-
Address non-dipping
Evening dosing and a sleep-apnoea review where night-time control is the issue.
-
Cardiology referral
For resistant, secondary or ambiguous patterns — a specialist takes it on.
-
Repeat ABPM at 6–12 months
To confirm response to treatment and re-check dipping and morning surge.
-
Home BP monitoring
For interim follow-up between ambulatory recordings.
-
Cardiovascular risk assessment
Bloods, ECG and imaging where the BP finding sits in a wider risk picture.
Recognised by major UK insurers
Cover depends on your policy and clinic; we confirm with your insurer before booking.
Frequently asked
Everything we get asked about ABPM recordings.
Quick answers on thresholds, dipping, morning surge, white-coat vs masked hypertension, and what happens after the report.
-
What does an ambulatory blood pressure recording show?
It shows your blood pressure across a full 24 hours — daytime and night-time averages, how much BP falls at night (dipping), the size of your morning surge, and whether clinic readings match real-life readings.
-
What ambulatory BP averages count as hypertension?
A daytime average above 135/85 mmHg is diagnostic of hypertension. A night-time average above 120/70 mmHg is nocturnal hypertension. Both are independent predictors of cardiovascular events.
-
What is dipping and why does it matter?
BP normally falls 10–20% overnight — a "normal dipper". A fall of less than 10% is non-dipping, and a rise at night is reverse dipping. Both are associated with higher stroke and cardiovascular risk.
-
What is morning surge?
The rise in BP from the lowest sleep reading into the early-morning hours. A surge greater than 55 mmHg has been linked to a higher stroke risk and often prompts a change in the timing of medication.
-
What is white-coat vs masked hypertension?
White-coat hypertension is raised BP in clinic but normal on ABPM — usually no treatment, but follow-up. Masked hypertension is the opposite — normal in clinic but raised on ABPM — and carries the same risk as sustained hypertension.
-
What happens after the report?
A normal recording earns reassurance and lifestyle advice. Confirmed hypertension is treated per NICE NG136. Non-dipping may prompt evening dosing or a sleep-apnoea review. Resistant or secondary patterns go to cardiology, with repeat ABPM at 6–12 months.
Sources
- NICE. Hypertension in adults: diagnosis and management (NG136).
- European Society of Hypertension. Practice guidelines for ambulatory blood pressure monitoring.
- British and Irish Hypertension Society. ABPM guidance and validated devices.
- Cochrane review on ambulatory blood pressure monitoring.
Reviewed by Pulse Atlas Editorial Board (). Next review: 2027-07-30. Estimated reading time: 6 minutes.
Related tests
Looking for a different test?
-
Ambulatory BP monitoring
The procedure itself — wearing the monitor for 24 hours.
Learn more -
Home BP monitoring
Self-measured home readings for interim follow-up.
Learn more -
Ambulatory ECG
A 24-hour heart-rhythm recording — the ECG equivalent.
Learn more -
All tests
Browse every test and procedure we arrange.
Learn more -
Hypertension
Related condition guide.
Learn more -
Atrial Fibrillation
Related condition guide.
Learn more -
Coronary Angioplasty
Related treatment option.
Learn more -
Coronary Artery Disease Treatment
Related treatment option.
Learn more
In practice, in London
Getting ambulatory blood pressure recording sorted in London, without the guesswork
With ambulatory blood pressure recording, the London question is usually about report turnaround and the radiologist reading it — not whether the scan is available. The wait for ambulatory blood pressure recording on the NHS depends heavily on where you live and how urgently the referral is graded. Central and West London private clinics can normally book within a week, with imaging or a procedure slot to follow shortly after. It’s worth being honest about the reason for going private: usually it’s time, not a fundamentally different test.
Once you’re in the private system for ambulatory blood pressure recording, the pace picks up noticeably. Consultant slots run to time, imaging is usually available in the same building or a short walk away, and the report comes back typed and detailed. It’s the coordination that tends to feel different — one person on the other end of the phone, not a switchboard. For ambulatory blood pressure recording specifically, the difference between a routine report and a sub-speciality read is where private care earns its keep.
The value of going through a concierge for ambulatory blood pressure recording isn’t access — anyone with an insurer or a credit card can get a private appointment in London. The value is knowing which consultant reads this particular presentation best, which unit turns reports around fastest, and which pathway won’t hit a dead end if the findings point somewhere unexpected.
Nearby in the library