High Blood Pressure
Our bodies have about 100,000 km of blood vessels through which our blood flows. This system of circulation is comprised of the heart and the veins and arteries that deliver blood to the body's organs and muscles. In order for flow to occur, a certain amount of pressure or force is required. This force or pressure, created by the heart as it contracts in a normal heartbeat, is exerted on the walls of the blood vessels, with the highest pressure occurring in the arteries. The body's blood pressure changes normally throughout the day, and with different levels of activity. These normal variations in pressure are normal, and not usually harmful. When blood pressure is too high over a long period of time, the extra force exerted by high blood pressure damages the smaller arteries of the body, and also damages the cells that line larger arteries. High blood pressure also exerts strain on the heart because it has to work harder to pump blood through the circulatory system. Over long periods of time, damage to small arteries, and artery walls, and the strain on the heart, can create what is called end organ damage.
The excess strain of high blood pressure is most evident in the kidney (which can cause kidney disease), in the brain (which can cause strokes), in the retina of the eyes (which can cause blindness), and in the arteries that supply the heart muscle (which can cause heart disease). High blood pressure can actually strain the heart so much, that the heart muscle's ability to contract is decreased. When this occurs, the heart's ability to work, as a pump is impaired, which can lead to heart failure.
High blood pressure is defined as a measure greater than 140/90. The top number is called the systolic pressure, and reflects the pressure in the blood vessels during each contraction of the heart. The lower number is called the diastolic pressure, which is the pressure in the vessels between heartbeats. Treating high blood pressure should lower blood pressure to less than 140/90. People with diabetes, pre-existing heart disease, or kidney problems should have their blood pressure goals even lower.
The cause of high blood pressure is not always known. People who smoke, are overweight, lead a sedentary lifestyle, and a have a family history of hypertension are at higher risk of high blood pressure. People with high blood pressure who start to exercise regularly, eat nutritious foods according to Canada's food guide, maintain a healthy weight, and stop smoking can sometimes lower high blood pressure through lifestyle changes alone. People with high blood pressure should reduce their salt intake.
If lifestyle changes alone do not lower a person's blood pressure, medication is often required. There are numerous types of medications that treat high blood pressure and can be prescribed by a family physician or specialist. The most accurate blood pressure readings are done manually by a nurse, nurse practitioner, or physician. Blood pressure readings from drug store machines are a good start but should be confirmed by a qualified professional. It is important to have your blood pressure tested at least every year as a senior, or if you have other health problems such as diabetes or high cholesterol. Young and middle-aged adults should have their blood pressure checked every two years.