Does Blood Pressure Drop at Night? What's Normal While You Sleep
Yes. Blood pressure usually falls about 10 to 20% during sleep, a pattern called dipping. Here's what's normal and why a home cuff can't check it.
This article is educational content, not medical advice. Always talk to a healthcare professional about your blood pressure.
The thresholds on this page follow the ACC/AHA guideline used in the United States (set in 2017 and kept in the 2025 update), which sets high blood pressure at 130/80 mmHg. Other bodies differ: ESH in Europe and NICE in the UK still define it at 140/90 mmHg. Check the guideline your own clinician uses.
Yes. In most people, blood pressure falls during sleep, usually by about 10 to 20% compared with the daytime average. Doctors call this "dipping". Pressure starts to climb again before you wake, and only a 24-hour monitor can reliably show whether your own night-time fall is smaller than that, or missing.
How much does blood pressure drop at night?
Mayo Clinic describes the daily pattern this way: blood pressure begins rising a few hours before you wake up, keeps rising through the day and peaks around midday, then drops in the late afternoon and evening and is normally lower at night while you sleep. Studies using 24-hour ambulatory blood pressure monitoring (ABPM), including the ABC-H analysis below, sort that night-time fall into four groups: a normal dip of 10 to 20%, reduced or "non-dipping" under 10%, extreme dipping over 20%, and "reverse dipping", where night pressure is higher than daytime. In the largest pooled analysis so far, the ABC-H meta-analysis of 17,312 people with high blood pressure, reduced dippers had a 27% higher risk of cardiovascular events than normal dippers, and reverse dippers had a higher risk of every outcome studied.
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Why does blood pressure go down when you sleep?
During sleep, your body is lying flat, still and not eating, and the nervous system that speeds the heart and tightens blood vessels quiets down. Heart rate slows, and pressure in the arteries follows.
Toward morning that system switches back on, which is why the "morning surge" happens around waking. Our post on morning vs. evening readings covers that rise in more detail.
The dip isn't a sign that anything is wrong. It's the expected rhythm. What researchers watch for is a dip that doesn't happen.
What counts as a normal night-time dip?
The dip is worked out as a percentage: take the average daytime systolic, subtract the average night-time systolic, and divide by the daytime figure. Here's how the categories look for someone whose daytime systolic averages 130 mmHg:
| Pattern | Night-time fall | Example night average (daytime systolic 130) |
|---|---|---|
| Extreme dipper | More than 20% | below 104 mmHg |
| Normal dipper | 10 to 20% | 104 to 117 mmHg |
| Reduced (non-) dipper | Less than 10% | 118 to 130 mmHg |
| Reverse dipper | Night higher than day | above 130 mmHg |
Across the ABC-H cohorts, the average night-to-day systolic ratio ran from 0.88 to 0.93. In other words, nights averaged only 7 to 12% lower than days, near the bottom of the normal range.
What does it mean if your blood pressure doesn't drop at night?
A reduced or reversed dip doesn't diagnose anything by itself, but it's worth knowing about because of the risk link above. A review by Cuspidi and colleagues notes that reverse dipping turns up often in people with high blood pressure, type 2 diabetes, chronic kidney disease and sleep apnea. Mayo Clinic lists the same kinds of conditions, plus poorly controlled high blood pressure, as reasons the daily pattern can look irregular.
Night-time pressure can also be too high on its own, whether or not it dips. Guideline bodies set their own lines for average readings taken during sleep on a 24-hour monitor:
- The ACC/AHA guideline, used in the US, treats a night-time ambulatory average of 110/65 mmHg as the match for its office threshold of 130/80.
- The ESH guideline, followed across much of Europe, defines night-time hypertension on ambulatory monitoring as 120/70 mmHg or higher, alongside an office line of 140/90.
These are averages from a full night of automatic readings. They aren't meant to be compared with a single number you take yourself.
Can a home monitor tell if you're a dipper?
Not reliably. A standard home cuff measures you while you're awake and sitting up, so a reading at bedtime is an evening reading, not a sleep reading. If you wake at 3 a.m. to take one, you're no longer asleep: you've sat up, the cuff has squeezed your arm, and you may need the bathroom, which can affect the reading too (see our post on whether a full bladder raises blood pressure).
That's why dipping is assessed with ABPM. You wear a cuff connected to a small recorder for 24 hours, and it inflates on its own at set intervals through the day and the night, so the night readings are taken while you sleep as normally as you can with a cuff on.
What your home log can do is give your clinician useful context. Consistently higher morning readings, readings that never seem to come down by evening, or a gap between home and clinic numbers (the pattern behind masked hypertension) are all reasonable things to bring to an appointment. So are loud snoring, pauses in breathing that someone else has noticed, or poor sleep. Your clinician can decide whether a 24-hour test makes sense.
If you take blood pressure medicine, questions about when to take it belong with your prescriber. Don't change the timing or dose based on a night-time pattern you've read about or measured yourself.
When a reading needs action, at any hour
A very high reading means the same thing at midnight as at noon. The American Heart Association calls a reading above 180/120 mmHg (either number) a hypertensive crisis. If it comes with chest pain, shortness of breath, back pain, numbness or weakness, vision changes or trouble speaking, seek medical help immediately.
With no symptoms, the AHA advises waiting about 5 minutes and measuring once more. If it's still above 180/120, seek medical help immediately. Don't keep re-measuring in the hope of a lower number.
Keeping a record your clinician can use
Spotting your own day-and-evening pattern starts with readings taken the same way, at the same times, with the time recorded. Our guide to taking an accurate reading at home covers the routine.
BPlus lets you log systolic, diastolic and pulse by hand, or scan the display of your own monitor with the camera. The time, date and arm are stamped automatically, so morning and evening readings sit side by side in your history and charts.
You can set daily reminders for both times, add a note (such as "slept badly"), and share a doctor-ready PDF or CSV export. BPlus doesn't measure blood pressure and can't tell whether you dip at night. It's a wellness and logging tool, not a medical device, and your data stays on your phone with no account needed.
Common questions about blood pressure at night
What time of night is blood pressure lowest? It's normally lowest while you're asleep, and according to Mayo Clinic it starts climbing again before you wake. Because the pattern follows sleep rather than the clock, the low point lines up with your own sleep hours, not a fixed time.
Is it normal for blood pressure to be higher at night? It isn't the usual pattern. Night pressure that's higher than daytime is called reverse dipping, and in the ABC-H meta-analysis it was linked to higher cardiovascular risk. It can only be confirmed with a 24-hour ambulatory monitor, so if you're concerned, ask your clinician whether that test is right for you.
Should I take my blood pressure before bed? An evening reading before bed is a normal part of home monitoring, and the AHA's home monitoring advice is to measure at the same times each day, morning and evening. Just remember it shows your evening pressure while awake, not what happens after you fall asleep.
Sources
- Mayo Clinic: Blood pressure: Does it have a daily pattern?
- Salles et al., 2016: Prognostic Effect of the Nocturnal Blood Pressure Fall in Hypertensive Patients: The ABC-H Meta-Analysis (Hypertension)
- Whelton et al., 2018: 2017 ACC/AHA Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults (Hypertension)
- Mancia et al., 2023: 2023 ESH Guidelines for the management of arterial hypertension (Journal of Hypertension)
- American Heart Association: Understanding Blood Pressure Readings
Medical disclaimer. BPlus is a wellness and informational tool that helps you record, organize and understand your blood pressure readings. It is not a medical device and does not diagnose, treat, cure or prevent any disease. BPlus does not measure blood pressure on its own. Always consult a qualified healthcare professional. Readings are not a substitute for a clinically validated blood pressure monitor.
