CLINICAL CONDITIONS PHYSICAL ACTIVITY AND HYPERTENSION By Amanda Radcliffe, MSc
DEFINING HYPERTENSION Hypertension is the term used to describe high blood pressure (BP). It is equivalent to systolic BP of more than 140 mm Hg and a diastolic BP above 90 mm Hg. Systolic pressure occurs when the heart contracts to pump blood and diastolic pressure occurs between contractions.
Blood pressure (BP) is the measure of the resistance to blood flow in the blood vessels. It is determined by cardiac output (the total amount of blood ejected from the heart per minute) and the resis- tance to blood flow (total peripheral resistance).
Blood pressure = cardiac output x total peripheral resistance
Blood pressure may rise or fall with an increase or decrease in one or both determinants of the above equation and is recorded by measuring both systolic and diastolic blood.
The borderline between normal and hypertension varies and target levels will differ from one individual to another. However blood pressure has been classified by the American College of Sports Medicine and the World Health Organisation who have identified mild to moderate hypertension as systolic blood pressures
(mm Hg) (mm Hg)
130-139 140-159 160-179 180-209 >210
100-109 110-119 >120
high - normal mild hypertension
moderate hypertension severe hypertension
very severe hypertension Table 1: Classification of blood pressure for adults (18 years and older)
between 140 to 180 mm Hg and diastolic blood pressures between 90 to 109 mm Hg (1,2,3). Optimal blood pressure is considered to be 120/80 mm Hg.
Hypertension is one of the most prevalent chronic diseases in the UK. Forty one percent of men and 33% of women in the UK are reported as having hypertension (4). Figure 1 clearly illustrates prevalence of hypertension among the different age groups and between men and women.
Individuals with mild to moderate hypertension have an increased risk of developing cardiovascular disease and stroke than nor- motensive individuals. Hypertensive individuals with blood pres- sures above 160/95 mm Hg have a higher risk of congestive heart failure and kidney damage than those with normal BP (2,5).