Hypertension · 01
Chapter 1: Definition of hypertension and blood-pressure classification
Definition of hypertension
According to the previous European guidelines (2018) and current international guidance, hypertension is defined by repeatedly elevated office systolic blood-pressure values above 140 mmHg and/or diastolic values above 90 mmHg. However, the relationship between blood pressure and cardiovascular or renal events, including fatal events, is continuous and begins at systolic values above 115 mmHg and diastolic values above 75 mmHg. The diagnostic definition is therefore partly arbitrary; its main purpose is to simplify diagnosis and decisions about hypertension management.
In this context, the thresholds above correspond to the blood-pressure level at which the benefits of an intervention—lifestyle modification or drug treatment—outweigh the benefits of no intervention, as demonstrated in randomised controlled trials (RCTs).
Classification of hypertension
The classification and grades of hypertension were not changed in the updated 2023 recommendations.
| Classification | Systolic (mmHg) | Diastolic (mmHg) | |
|---|---|---|---|
| Optimal | <120 | and | <80 |
| Normal | 120–129 | and | 80–84 |
| High-normal | 130–139 | and/or | 85–89 |
| Grade 1 hypertension | 140–159 | and/or | 90–99 |
| Grade 2 hypertension | 160–179 | and/or | 100–109 |
| Grade 3 hypertension | >180 | and/or | >110 |
| Isolated systolic hypertension | >140 | and | <90 |
| Isolated diastolic hypertension | <140 | and | >90 |
The blood-pressure category is determined by the highest measured level, whether the higher value is systolic or diastolic.
In addition to grades based on blood-pressure values, hypertension is also described by stages:
Stage 1: Uncomplicated hypertension, without HMOD or cardiovascular disease; chronic kidney disease (CKD) stages 1 and 2 are included in this stage.
Stage 2: HMOD, CKD stage 3, or diabetes.
Stage 3: Established cardiovascular disease or CKD stages 4 or 5.
Prevalence of hypertension
Hypertension is the most common cardiovascular disorder worldwide. According to the World Health Organization, it affects 1.28 billion adults aged 30–79 years globally, two-thirds of whom live in low- and middle-income countries.
At younger ages, below 50 years, hypertension is more common in men. In women, systolic blood pressure rises sharply from the third decade of life and rises further after menopause; consequently, hypertension becomes more prevalent among older women, particularly after 65 years. Systolic blood pressure increases progressively with age, whereas diastolic blood pressure rises only until approximately 50–60 years, followed by a short plateau and then a gradual decline. This contributes to a widening pulse pressure—the difference between systolic and diastolic pressure—with advancing age.
Blood pressure and the risk of cerebrovascular, cardiovascular and kidney events
There is a continuous relationship between higher blood pressure and the risks of stroke, coronary artery disease (CAD), heart failure (HF), and progression of CKD. This relationship applies across ages and ethnic groups.
In 2002, the Prospective Studies Collaboration reported that each 20-mmHg increase in office systolic blood pressure or 10-mmHg increase in office diastolic blood pressure approximately doubled the risk of fatal coronary disease or stroke. After the age of 50, systolic blood pressure is a better predictor of events than diastolic blood pressure.
Earlier studies suggested that diastolic hypertension was particularly associated with increased risk in younger people. More recent studies indicate increased cardiovascular risk from elevations in both systolic and diastolic pressure among younger adults. Increased pulse pressure, a marker of arterial stiffness, is also associated with an adverse prognosis, in addition to the risk associated with higher systolic pressure in middle-aged and older adults.
Hypertension and assessment of total cardiovascular risk
Hypertension commonly coexists with other risk factors, including dyslipidaemia, impaired glucose tolerance and type 2 diabetes, which further increase cardiovascular risk. Many environmental, lifestyle and biological factors influence cardiovascular risk in people with hypertension.
Women also have sex-specific risk factors, including hypertensive disorders of pregnancy and premature menopause.
Hypertension-mediated organ damage (HMOD) is an important intermediate stage in the cardiovascular disease pathway, between cardiovascular risk factors and clinically established cardiovascular disease or advanced CKD stages 4 and 5. HMOD is also an important determinant of cardiovascular risk, which is usually high when HMOD is present.
Diabetes is classified as a separate condition affecting cardiovascular risk, regardless of whether HMOD, cardiovascular disease or CKD is also present. People with diabetes are considered to have moderate risk only when diabetes is recent—less than 10 years in duration—well controlled, and unaccompanied by HMOD or other cardiovascular risk factors.
Total cardiovascular risk should be estimated in every patient with hypertension because it influences management. Computer-based risk models have been developed, many based on the Framingham study, which estimates 10-year risk of fatal and non-fatal coronary disease using systolic blood pressure and other risk factors. Because the incidence of coronary events and stroke differs geographically between European and American populations, the SCORE system was developed from a large European database. SCORE charts estimate the 10-year risk of fatal cardiovascular disease, not only coronary disease, in high- and low-risk European countries. Modified SCORE2 and SCORE2-OP are also available, including for older adults.
Total risk should be stratified in all patients. Stratification is especially important in people with high-normal blood pressure or grade 1 hypertension, because it may influence whether drug treatment should be started and how quickly. Drug treatment is generally indicated regardless of cardiovascular risk in grade 2 and grade 3 hypertension, but risk stratification remains important for several other treatment decisions.
Confirming the diagnosis of hypertension
Because blood pressure varies over time, office hypertension—systolic pressure of 140 mmHg or diastolic pressure of 90 mmHg—should usually be confirmed over at least two or three visits, unless the first visit shows marked elevation, such as grade 3 hypertension, or high cardiovascular risk including HMOD.
Although the available evidence has diagnostic limitations and ambulatory or home measurements can be difficult to collect routinely, out-of-office blood-pressure measurements provide important clinical information. Whenever possible, ambulatory blood-pressure monitoring (ABPM), home blood-pressure monitoring (HBPM), or both should therefore be obtained when office pressure is elevated, to confirm the diagnosis and identify specific blood-pressure phenotypes. ABPM and/or HBPM are particularly useful when office values vary substantially between visits.