for adults aged 40 to 69

every 20 mmHg increase in systolic blood pressure

or 10 mmHg increase in diastolic blood pressure

Doubles

the risk of death from coronary artery disease

High blood pressure (hypertension) is a very common condition, affecting 1 in 4 adults in the UK and 70% of people over 70 years of age. There is a direct relationship between high blood pressure readings and the incidence of coronary artery disease and stroke:

half of coronary artery disease cases

and two thirds of stroke cases

are due to raised blood pressure

Blood pressure changes throughout the day, tending to be highest in the morning and lowest in the evening. It can rise transiently with stress and will be higher during physical activity than before.

30-40% of patients who have high blood pressure readings with a doctor are actually suffering from “white coat hypertension” and have normal blood pressures outside of a clinic setting, and equally 15% of people have “masked” hypertension, where blood pressure is normal with a doctor but high elsewhere. 

Blood pressure measurements vary depending on how and where they are measured. Measurements with a doctor, known as office blood pressure readings, are generally higher than measurements obtained by individuals using a home blood pressure monitor or with a 24 hour blood pressure monitor known as ambulatory blood pressure monitoring.

A number of different factors influence the point at which a patient would benefit from medication to lower blood pressure, but broadly speaking the following apply, based on office readings:

However, in patients with a history of cardiovascular disease, treatment is recommended with readings of ≥130/≥80, and in frail patients the threshold should be individualised.