High blood pressure

Further Information

• American Heart Association
• Blood Pressure.com
• British Heart Foundation
• Heart and Stroke Foundation of Canada
• Heart Information Network

Interactive Learning

Blood pressure is the force of the blood against the walls of arteries when the heart beats and when it is at rest. It is measured in millimetres of mercury (mm Hg) using an inflatable blood pressure cuff placed around the arm.

High blood pressure (or hypertension) is defined as a blood pressure greater than 140/90 mm Hg (i.e. 140 over 90) on several readings. People with high blood pressure are more likely to develop coronary heart disease (which leads to heart attack) and stroke.

Symptoms

High blood pressure is a silent disease. Most people with high blood pressure don't have any symptoms, so they don't know if they have it unless their blood pressure is checked. The causes of high blood pressure vary. Disorders such as diabetes and high blood cholesterol may contribute to high blood pressure.

Treatment

The goal of treatment is to prevent health complications that may occur as a result of high blood pressure. Adopting healthy lifestyle habits are effective first steps for controlling and preventing high blood pressure. If lifestyle changes alone are not effective in keeping your pressure controlled, it may be necessary to add blood pressure medications.

Many types of medications to lower blood pressure are available. They lower your blood pressure in different ways. The main types of medications include:

• Diuretics - These medications are sometimes called ‘water pills’ because they work in the kidney and flush excess water and sodium from the body.
• Beta-blockers - These medications block effects of certain chemicals, which make the heart beat more slowly and less forcefully.
• Angiotensin converting enzyme (ACE) inhibitors prevent the formation of a hormone that normally causes blood vessels to narrow. The ACE inhibitors cause the vessels to relax and blood pressure goes down.
• Angiotensin II receptor blockers help relax blood vessels by blocking the action — not the formation — of a naturally occurring chemical that narrows blood vessels. As a result, the vessels become wider and blood pressure goes down.