SBP

Systolic blood pressure: ESC 2024 categories, correct measurement, causes of high and low values and when to seek care.

Systolic blood pressure (SBP) is the upper number of a blood-pressure reading: the peak pressure in the arteries when the heart contracts and ejects blood. It depends on the force of the heartbeat, the volume ejected and the stiffness of the large arteries. With age, arteries become stiffer, so systolic pressure tends to rise. Raised systolic pressure is the strongest blood-pressure predictor of stroke, heart attack, heart failure and kidney disease.

Blood pressureHypertensionCardiovascular risk

Non-elevated (ESC 2024)< 120 mmHg

Elevated120–139 mmHg

Hypertension≥ 140 mmHg (office)

Treatment target120–129 mmHg if tolerated

Figure 1. Office systolic blood pressure categories (ESC 2024). Very low values below about 90 mmHg with symptoms are also abnormal.

Measuring correctly

Sit quietly for 5 minutes, back supported, feet on the floor, arm at heart level; no coffee, smoking or exercise for 30 minutes before
Use a validated device with a cuff of the right size; take 2–3 readings 1–2 minutes apart and average them
Home or 24-hour ambulatory measurements help to exclude "white-coat" hypertension and to find "masked" hypertension. The home threshold for hypertension is ≥ 135/85 mmHg.

Causes of high systolic pressure

Most hypertension is primary (essential), linked to genetics, age, excess salt and alcohol, overweight and inactivity. Isolated systolic hypertension (high systolic, normal diastolic) is typical of older people with stiff arteries. Secondary causes include kidney disease, primary aldosteronism, sleep apnoea, thyroid disease, coarctation of the aorta and medicines (NSAIDs, decongestants, oral contraceptives, corticosteroids).

Low systolic pressure

Low pressure without symptoms is often normal in young, slim, fit people. It becomes important when it causes dizziness, fainting, falls or confusion. Causes include dehydration, blood loss, blood-pressure medicines, standing up quickly (orthostatic hypotension), heart disease, sepsis and adrenal insufficiency.

Seek emergency care

if blood pressure is 180/120 mmHg or higher together with chest pain, breathlessness, severe headache, confusion, visual disturbance, weakness or speech problems, or if low pressure comes with fainting or signs of shock.

Planned evaluation

Repeated readings of 140/90 mmHg or more in the clinic (or 135/85 at home) need medical assessment. Less salt, more vegetables, regular exercise, weight loss and limiting alcohol lower blood pressure.

References

McEvoy JW, McCarthy CP, Bruno RM, et al. 2024 ESC Guidelines for the management of elevated blood pressure and hypertension. Eur Heart J. 2024;45(38):3912–4018. doi:10.1093/eurheartj/ehae178

This article is for general information and does not replace a consultation with a doctor. Measurements must be interpreted by a physician together with symptoms and other tests.

Published on 2 June 2019

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