High Blood Pressure: introduction
High blood pressure increases the risk of disease and death in the population. As a clinical risk factor, it is of major public health importance and compared to other leading risk factors accounts for the third largest proportion of disability adjusted life years lost globally after dietary factors and cigarette smoking (Forouzanfar et al, 2016).
Blood is circulated through the body by the heart, and the beating of the heart leads to peaks and troughs in blood pressure. The peaks are called systolic and the troughs diastolic. Blood pressure is measured as systolic/diastolic, e.g. 140/90 mmHg (pressure equivalent of millimetres of mercury).
Blood pressure varies normally from minute to minute, and over days and weeks, but a consistently raised blood pressure increases the risk of certain diseases. Cardiovascular risk increases above values of 115/70, (SIGN 149) but blood pressure persistently above 140/90 mmHg is accepted as an appropriate reason to consider treatment. (NICE guideline NG136, 2019).
The measurement of blood pressure is an important consideration because it requires a certain level of skill, an appropriate setting and well maintained and calibrated equipment. A measurement should be based on at least two readings.
High blood pressure increases the risk of a range of diseases:
- coronary heart disease (angina, heart attack)
- stroke (both that due to a blood clot and that due to bleeding)
- heart failure (heart strain - especially left ventricular)
- aortic aneurysm (dilated aorta with risk of rupture and massive internal haemorrhage)
- peripheral vascular disease (reduced blood supply to the limbs)
- chronic kidney disease (including renal failure)
- retinal disease (visual impairment)
