2002Lancet
Lewington et al.
~1 million adults, 61 studies
From 115/75 upwards, every 20 mmHg higher systolic pressure doubled the risk of dying from heart disease or stroke, with no safe threshold.
Find on PubMed ↗Research library · Heart & fitness
Blood pressure: the silent load on your arteries
The force of blood pushing on your artery walls. High blood pressure rarely causes symptoms, yet it's the world's leading risk factor for death, wearing out the heart, brain, kidneys and eyes year after year.
Strong evidenceUpdated Oct 2026 · 4 new studies2×risk of dying from heart disease or stroke for every 20 mmHg higher (top number)Lewington 2002, Lancet, ~1M people in 61 studies
−13%death risk for every 10 mmHg the top number comes downEttehad 2016, Lancet, 123 trials, 600,000+ people
−27%death risk with a target under 120 vs under 140SPRINT 2015, NEJM, 9,361 people
01
The basics
What the two numbers mean
Blood pressure is written as two numbers, like 118/76 mmHg. The top (systolic) number is the peak pressure when your heart squeezes. The bottom (diastolic) number is the pressure while your heart relaxes and refills.
Your arteries are elastic tubes. When pressure stays high, their walls thicken and stiffen, the heart has to work harder and grows thick, and tiny vessels in the brain, kidneys and eyes get damaged. That is why high blood pressure raises the risk of heart attack, stroke, heart failure, kidney disease and dementia.
Current US guidelines call under 120/80 normal, 120–129 'elevated', 130–139 (or 80–89) stage 1, and 140/90 or more stage 2 high blood pressure. Nearly half of adults in many countries have readings above normal, and many don't know it.
Reading the two numbers
Each heartbeat sends a pressure wave through your arteries. The peak is the top number, the trough the bottom number.
02
How it works
How high pressure does damage
1
Arteries
Constant force injures the lining, making it stiffer and easier for plaque to stick.
2
Heart
Pumping against high pressure thickens the heart wall and can lead to heart failure.
3
Brain
Small vessel damage raises the risk of stroke, memory problems and dementia.
4
Kidneys & eyes
Delicate filters and retina vessels get scarred over time.
03
Measure it
How to measure it at home
- Use a validated upper-arm cuff (wrist cuffs are less accurate). Check the cuff size fits your arm.
- Sit quietly for 5 minutes, back supported, feet flat, arm resting at heart level. No coffee, exercise or smoking for 30 minutes before.
- Take 2 readings a minute apart, morning and evening, for 7 days, and average them. Home readings avoid the 'white coat' effect at the clinic.
Try your number
NormalElevatedStage 1 highStage 2 high
95170
Categories from the ACC/AHA guideline. The bottom number counts too: 80–89 is stage 1, 90 or more is stage 2.
04
What the research says
The key studies
2016Lancet
Ettehad et al.
123 trials, 613,815 people
Each 10 mmHg drop in systolic pressure cut major heart events by 20%, stroke by 27%, heart failure by 28% and death by 13%, whatever the starting level.
Find on PubMed ↗2015NEJM
SPRINT Research Group
9,361 adults at high risk
Aiming for under 120 rather than under 140 reduced heart attacks, strokes and heart failure by 25% and deaths by 27%.
Find on PubMed ↗2019JAMA
SPRINT MIND
9,361 adults
The tighter target lowered the risk of mild memory and thinking problems by 19%.
Find on PubMed ↗2013BMJ
He et al.
34 trials
Cutting salt by about 4.4 g a day lowered blood pressure by around 4/2 mmHg on average, and more (5/3) in people with high blood pressure.
Find on PubMed ↗2023Br J Sports Med
Edwards et al.
270 trials, 15,827 people
All exercise types lowered blood pressure, and isometric holds like wall sits and handgrip squeezes gave the largest drop: about 8/4 mmHg.
Find on PubMed ↗05
New in 2025–26
What the newest research adds
The 2025 US guideline now backs earlier treatment, a target under 130/80 partly to protect the brain, and potassium salt substitutes. Swapping salt cut repeat strokes and deaths, while the time of day you take your pills turned out not to matter.
The new studies, in order
Every study added to this page since January 2025. Green rings are the strongest evidence: large trials or meta-analyses.
Swapping salt cut repeat strokes
SSaSS follow-up, 2025, 15,249 stroke survivors. Events per 1,000 people per year with ordinary salt vs a potassium salt substitute.
NewAug 2025J Am Coll Cardiol
Jones et al. (AHA/ACC guideline)
National clinical guideline
Keeps the target below 130/80. Adults at 130 to 139 over 80 to 89 should start medicine if lifestyle changes have not worked after 3 to 6 months, even at low risk. It newly recommends potassium salt substitutes, salt ideally 1,500 mg sodium a day, and avoiding alcohol, or at most 2 drinks a day for men and 1 for women.
Strong evidenceRead the source ↗
NewNov 2024NEJM
Bi et al. (BPROAD)
12,821 adults with type 2 diabetes, 4.2 years
Aiming for a top number under 120 rather than under 140 cut heart attacks, strokes and heart deaths by 21%. Low blood pressure symptoms and high potassium were a bit more common. Printed in the journal in 2025.
Strong evidenceRead the source ↗
NewFeb 2025JAMA Cardiol
Ding et al. (SSaSS)
15,249 stroke survivors in 600 Chinese villages, 5 years
Using a potassium salt substitute instead of ordinary salt cut repeat strokes by 14% and deaths by 12%, with no rise in dangerous potassium levels. Not for people with kidney disease or on potassium-raising drugs without advice.
Strong evidenceRead the source ↗
NewMay 2025JAMA
Garrison et al. (BedMed)
3,357 adults with high blood pressure, 4.6 years
Taking blood pressure pills at bedtime rather than in the morning made no difference to heart attacks, strokes, heart failure or death (hazard ratio 0.96). This challenges earlier claims that night-time dosing halves risk: take them when you will remember.
Strong evidenceRead the source ↗
What this changes for you
Aim for under 130/80, and if you sit at 130 to 139 for a few months despite lifestyle changes, ask about medicine. Swap table salt for a potassium salt substitute unless you have kidney disease or take potassium-raising drugs. Take pills whenever you'll remember them.
06
Take action
How to lower it
Each change below lowers blood pressure by a few points. Together they can match a medicine.
- 1
Eat the DASH way
Plenty of vegetables, fruit, beans, nuts and low-fat dairy, less red meat and sweets. Cut about 11 points in people with high blood pressure (Appel 1997).
- 2
Cut salt, add potassium
Aim for under 5 g salt a day. Most comes from bread, cheese, processed meat and ready meals. Potassium-rich foods (beans, bananas, leafy greens) help.
- 3
Move, including isometrics
Cardio most days, plus 3 sessions a week of 4×2-minute wall sits or handgrip squeezes.
- 4
Lose a little weight
Roughly 1 mmHg lower for every kilogram lost.
- 5
Drink less, sleep better
Alcohol raises pressure. Loud snoring can mean sleep apnea, a common hidden cause.
- 6
Take medicine if needed
If home readings stay at 130/80 or more, talk to your doctor. Pills are safe, cheap and very effective.
07
Myth or fact
Common myths, checked
✕ MythI'd feel it if my blood pressure were high.
✓ FactIt's called the silent killer because most people feel nothing until damage is done.
✕ MythIt's normal for it to rise with age.
✓ FactIt's common, not harmless. Risk keeps climbing with every point.
✕ MythOnce I start pills, I'm on them for life.
✓ FactSome people can reduce or stop medicine after big lifestyle changes. Never stop without your doctor.
✕ MythOnly the top number matters.
✓ FactBoth count, especially the bottom number in people under 50.
08
Questions
Frequently asked
How often should I check?
If it's normal, at least once a year. If it's raised or you're changing treatment, a week of home readings every month or two.
Why is it higher at the doctor's?
'White coat' nerves can add 10 points or more. Home readings give the truer picture.
Is low blood pressure a problem?
Only if it causes dizziness or fainting. Otherwise, lower is usually healthier.
09
Test yourself
True, partly true or myth?
Read each claim and pick an answer: the card flips to show the verdict and why. Not sure? Use “Just reveal”.
Card № 01True or myth?
High blood pressure usually causes no symptoms at all.
True
High blood pressure usually causes no symptoms at all.
That's why it's called a silent killer. The only way to know is to measure it.
Card № 02True or myth?
Headaches and nosebleeds are reliable signs of high blood pressure.
Myth
Headaches and nosebleeds are reliable signs of high blood pressure.
Most people with high blood pressure have neither. Only very high readings in a crisis tend to cause headaches.
Card № 03True or myth?
Cutting salt lowers blood pressure in most people, especially those whose pressure is already high.
True
Cutting salt lowers blood pressure in most people, especially those whose pressure is already high.
Trials like DASH-Sodium show clear drops; swapping to a potassium salt substitute also cut strokes in the SSaSS trial.
Card № 04True or myth?
Home readings are often more useful than one reading at the clinic.
True
Home readings are often more useful than one reading at the clinic.
'White coat' pressure can be high at the doctor. An average of home readings over a week is closer to your real level.
Card № 05True or myth?
A reading of 130/85 is fine.
Partly true
A reading of 130/85 is fine.
It used to be called normal. Current US guidelines call 130–139 systolic stage 1 high; European ones call it high-normal. Either way it's worth acting on.
Card № 06True or myth?
Once your blood pressure is normal on pills, you can stop them.
Myth
Once your blood pressure is normal on pills, you can stop them.
The pills are usually what's keeping it normal. Stop only with your doctor, and usually after lifestyle changes have done real work.
Card № 07True or myth?
Isometric exercise like wall sits and plank holds lowers blood pressure well.
True
Isometric exercise like wall sits and plank holds lowers blood pressure well.
A 2023 meta-analysis (Edwards, BJSM) ranked isometric training as the most effective exercise type for lowering resting pressure.
Card № 08True or myth?
Sitting with your arm unsupported or legs crossed can push the reading up.
True
Sitting with your arm unsupported or legs crossed can push the reading up.
Sit back, feet flat, arm resting at heart level, and rest 5 minutes before measuring.
Card № 09True or myth?
Coffee raises blood pressure.
Partly true
Coffee raises blood pressure.
It causes a short rise for a few hours, especially in people who don't drink it often. Regular moderate coffee isn't linked to long-term high pressure.
Card № 10True or myth?
Blood pressure naturally goes up with age, so it's nothing to worry about.
Myth
Blood pressure naturally goes up with age, so it's nothing to worry about.
It's common, but not harmless. Every 20 mmHg higher systolic pressure roughly doubles heart disease and stroke risk.
Nothing here yet. Try another filter.
10
Sources
References and related topics
- Lewington et al. (2002). Lancet. ~1 million adults, 61 studies. PubMed ↗
- Ettehad et al. (2016). Lancet. 123 trials, 613,815 people. PubMed ↗
- SPRINT Research Group (2015). NEJM. 9,361 adults at high risk. PubMed ↗
- SPRINT MIND (2019). JAMA. 9,361 adults. PubMed ↗
- He et al. (2013). BMJ. 34 trials. PubMed ↗
- Edwards et al. (2023). Br J Sports Med. 270 trials, 15,827 people. PubMed ↗
- Jones et al. (AHA/ACC guideline) (2025). J Am Coll Cardiol. National clinical guideline. Source ↗
- Bi et al. (BPROAD) (2024). NEJM. 12,821 adults with type 2 diabetes, 4.2 years. Source ↗
- Ding et al. (SSaSS) (2025). JAMA Cardiol. 15,249 stroke survivors in 600 Chinese villages, 5 years. Source ↗
- Garrison et al. (BedMed) (2025). JAMA. 3,357 adults with high blood pressure, 4.6 years. Source ↗