What is normal blood pressure?

Given the continuous relations of blood pressure to cardiovascular risk, any definition of high blood pressure is arbitrary, and based on thresholds at which there is clear evidence that treatment benefits outweigh potential risks. This review examines what constitutes optimal blood pressure.

A recent report raised the possibility of an age- and sex-dependent threshold for risk associated with systolic blood pressure, questioning the use of a single threshold (such as 140/90 mmHg) for defining hypertension. Several subsequent studies have questioned this notion and reemphasized that lower blood pressure levels are associated with less morbidity and mortality even within the nonhypertensive range. A recent meta-analysis confirmed that a blood pressure of 115/75 mmHg is associated with minimal vascular mortality and likely constitutes optimal blood pressure. Such blood pressure levels are infrequent in westernized societies. The target blood pressure goal for treated hypertensives is higher at 140/90 mmHg but is infrequently achieved. Select individuals at high absolute risk of cardiovascular disease events and/or with specific conditions (notably diabetes, renal insufficiency and prior vascular disease) may benefit from blood pressure lowering below this threshold.

At a population level, a blood pressure of 115/75 mmHg seems optimal because it is associated with minimal vascular risk. Over half of all hypertensives do not have their blood pressure controlled underscoring the challenges facing health care providers. Efforts should be strengthened for the primary prevention of hypertension and the promotion of optimal blood pressure through lifestyle measures.