Registered Nurses' Association of Ontario

Hypertension - Background Information

  • Hypertension is a complex, chronic condition that is often referred to as the “silent killer”.  As clients are often asymptomatic, detection and treatment delays may occur which may result in the development of target organ damage and other debilitating complications.
  • The overall prevalence of hypertension (defined as blood pressure > 140/90 mmHg) for Canadians aged 18-74 is 21% according to the Canadian Heart Health Survey, and prevalence is known to rise progressively with age.  The Heart and Stroke Foundation of Ontario estimates that more than 2.4 million or 22% of Ontarians have hypertension.
  • The recently completed Heart and Stroke Foundation of Ontario (2009) survey of blood pressure awareness treatment and control found unprecedented levels of blood pressure control with two out of three people with hypertension under control.
  • The pathophysiology of hypertension is complex and much is still unknown about the underlying causes of the condition. In a small number of individuals (between 2 and 5%), hypertension is attributable to secondary causes such as renal or adrenal disease. In the vast majority of individuals, however, no clear identifiable cause is found and the condition is labelled “essential” hypertension.
  • Research has shown that there are a number of interrelated factors that contribute to elevated blood pressure including salt intake, obesity, insulin resistance, the renin-angiotensin system and the sympathetic nervous system.
  • High blood pressure increases the risk of ischemic heart disease 3-to-4 fold and of overall cardiovascular risk by 2-to-3 fold. The incidence of stroke increases approximately 8-fold in persons with definite hypertension. It has been estimated that 40% of cases of acute myocardial infarction or stroke are attributable to hypertension.
  • The prevention and control of hypertension has a major impact on health, quality of life, disability and death among Canadians.
  • Despite the availability of effective treatments, studies have shown that in many countries less than 25% of clients treated for hypertension achieve optimum blood pressure control. In Canada, for example, only 21% of clients treated for high blood pressure had their blood pressure controlled.
Chronic Disease
Nursing Management of Hypertension
Background Information