Patient or family

From a high blood pressure reading to stroke prevention

A suggested order for reading this atlas, for an adult who has been told they have a high blood pressure reading, and for their family. It starts with what a reading and a diagnosis mean, goes through measuring at home and on a device you can check, then medicines, salt and stroke, and ends with prevention and questions to take to your care team. It is not medical advice and it does not cover pregnancy.

1. Hypertension (high blood pressure) High blood pressure, called hypertension, means blood pressure that stays higher than it should over time. Guidelines set different thresholds, so each number in this atlas is tied to the guideline that gives it.
2. Blood pressure Blood pressure is how hard the blood pushes on the arteries and other blood vessels. A device reports two values, a systolic one and a diastolic one. This page shows what two guidelines say about the numbers. NICE confirms a diagnosis in adults when the clinic reading is 140/90 mmHg or higher and the daytime ambulatory average or the home average is 135/85 mmHg or higher. The European Society of Cardiology's summary adds a category called elevated blood pressure. The two are shown side by side and are not merged. NICE says its content is not meant as a basis for decisions outside the United Kingdom.
3. Ambulatory blood pressure monitoring (ABPM) Ambulatory blood pressure monitoring means taking repeated readings through your usual waking hours. NICE recommends offering it to confirm a diagnosis in adults whose clinic reading is between 140/90 and 180/120 mmHg. NICE does not say it is the only or best way to confirm the diagnosis.
4. Home blood pressure monitoring Home blood pressure monitoring means measuring your own blood pressure with a device, at home or elsewhere outside the clinic. NICE recommends offering it to confirm a diagnosis when ambulatory monitoring is unsuitable or the person cannot tolerate it.
5. Automated upper-arm cuff blood pressure device This is a device with a cuff for the upper arm that works out the reading itself from signals in the cuff. Even a validated device has to be used in a standard way, for example with a cuff of the right size, at heart level, on a bare upper arm. NICE puts a duty on healthcare providers: every blood pressure device they use must be properly validated, kept in working order and recalibrated on a regular schedule. The NICE text does not say what properly validated means.
6. STRIDE BP validated device lists STRIDE BP is a group that keeps lists of validated blood pressure monitors on its own website. This atlas names and links that resource and does not restate what it lists. You can search it for a monitor. Not being on a list does not by itself show that a monitor is inaccurate.
7. Cuffless blood pressure monitoring Many devices that measure blood pressure without an inflating cuff are on sale, and they claim to be accurate. A 2022 statement from a European hypertension expert group says recent European Society of Hypertension guidelines do not recommend them for diagnosis or management, and that questions about their accuracy must be answered first. A 2023 statement sets out six validation tests. This page does not say that any such device is accurate.
8. Blood pressure lowering medicine For adults whose high blood pressure is confirmed, WHO recommends that those who need medicine start with a drug from one of three classes: thiazide and thiazide-like agents, ACE inhibitors or angiotensin-receptor blockers, or long-acting dihydropyridine calcium channel blockers. WHO also suggests starting with a combination of these drugs, preferably in a single pill. The page shows both statements and the pressures at which WHO says to start medicine. It also shows a pooled analysis of 48 trials, which found that a 5 mm Hg lower systolic pressure from treatment went with a lower risk of a major cardiovascular event. The analysis says nothing about one drug or about benefit for one person.
9. Salt substitution (lower-sodium, potassium-containing salt) A salt substitute swaps part of the sodium in table salt for potassium. In SSaSS, a trial in rural China among people who had had a stroke or were 60 or older with high blood pressure, villages that used a substitute had fewer strokes and fewer deaths than villages that kept regular salt. WHO suggests that adults in general populations who use table salt could replace it with a potassium-containing substitute. WHO says this is not intended for pregnant women, children, or people with kidney impairment or other conditions that might make it harder to clear potassium. NICE says older people, people with diabetes, people with kidney disease, and people on some blood-pressure medicines (for example ACE inhibitors and angiotensin II receptor blockers) should not use salt substitutes that contain potassium chloride, and says these groups should be encouraged to cut down on salt instead. The two bodies name different groups, and their positions are shown side by side and are not merged.
10. Stroke A stroke is a sudden loss of brain function. It happens when part of the brain does not get enough blood or when there is bleeding inside the skull. A 2012 WHO guideline describes high blood pressure as a major risk factor for cardiovascular disease, in particular for heart attack and stroke. It does not say that lowering blood pressure prevents stroke. This page also lists the SSaSS salt-substitute trial, which counted strokes.
11. Preventing heart attack, stroke and heart failure This is the starting page for the atlas's prevention material. So far it is built around blood pressure, and it holds one piece of evidence, the pooled analysis of blood-pressure-lowering medicines shown on the medicine page. Questions you could take to your care team: What blood pressure target applies to me? How often should I check at home? Is a potassium salt substitute safe for me? They are questions, not advice, and this atlas does not give the answers.