In the US alone, around 75 million people have hypertension
, with more people dying of hypertension-related cardiovascular disease than from the next three deadliest diseases combined.10
In 2011-2012 in the US, about a third of all people over the age of 20 years had hypertension, based on high blood pressure assessments and the number of people taking antihypertensive medications.2
Control of hypertension has become a key national priority in the US as part of the Million Hearts initiative from the Department of Health and Human Services, which aims to prevent 1 million heart attacks and strokes in the US by 2017.3
The increasing prevalence of the condition is blamed on lifestyle and dietary factors, such as physical inactivity, alcohol and tobacco use, and a diet high in sodium (usually from processed and fatty foods).1
This page offers detailed but easy-to-follow information about hypertension. Should you be interested in the latest scientific research on hypertension, please see our hypertension news section.
Blood pressure is the force exerted by the blood against the walls of blood vessels, and the magnitude of this force depends on the cardiac output and the resistance of the blood vessels.4
What is hypertension (high blood pressure)?
Hypertension is defined as having a blood pressure higher than 140 over 90 mmHg, with a consensus across medical guidelines.1,5
This means the systolic reading (the pressure as the heart pumps blood around the body) is over 140 mmHg (millimeters of mercury) and/or the diastolic reading (as the heart relaxes and refills with blood) is over 90 mmHg.
This threshold has been set to define hypertension for clinical convenience as patients experience benefits once they bring their blood pressure below this level.6
However, medical experts consider high blood pressure as having a continuous relationship to cardiovascular health.1,6 They believe that, to a point, the lower the blood pressure the better (down to levels of 115-110 mmHg systolic, and 75-70 mmHg diastolic).1
This view has led the American Heart Association (AHA), for example, to define the following ranges of blood pressure (in mmHg):
- Normal blood pressure is below 120 systolic and below 80 diastolic
- Prehypertension is 120-139 systolic or 80-89 diastolic
- Stage 1 high blood pressure (hypertension) is 140-159 systolic or 90-99 diastolic
- Stage 2 high blood pressure (hypertension) is 160 or higher systolic or 100 or higher diastolic
- Hypertensive crisis (a medical emergency) is when blood pressure is above 180 systolic or above 110 diastolic.
