Hypertension: The Facts
Heart disease is one of the leading causes of death worldwide - and people who have abnormally high pressure in their arteries are far more likely than others to die prematurely of heart disease.
Your arteries carry the blood from your heart throughout your body. Blood pressure is the measure of how hard your blood is pushing against the inside of your arteries. Although a certain amount of pressure is needed to carry the blood through your body, if that pressure is too great, you have high blood pressure, or hypertension.
When blood pressure is measured, there are two numbers for each reading: for example, "one-twenty over eighty," written as 120/80. This is because each heartbeat sends a pressure wave through the bloodstream. The higher figure (systolic blood pressure) is the peak of the wave. The lower figure (diastolic blood pressure) is the lower "dip" or trough of the wave. Blood pressure is always recorded as the systolic number over the diastolic number; the numbers indicate pressure as measured in millimetres of mercury on the gauge (mm Hg). Anyone over 140 systolic or 90 diastolic has high blood pressure.
Hypertension is one of the main risk factors for heart disease, stroke, and kidney failure. In Canada, it has been estimated that 25% of men and 18% of women have high blood pressure. Many are not aware of the problem. Of those who are, less than one-third receive adequate treatment to control their blood pressure.
Causes
Primary (or essential) hypertension is when the cause is unknown. The majority of hypertension cases are primary. When there is an underlying problem such as kidney disease or hormonal derangements that can cause hypertension, it is called secondary hypertension. When it is possible to correct the underlying cause, high blood pressure usually improves or may even return to normal.
Other factors that can contribute to hypertension include:
- age (blood pressure usually increases with age)
- diet
- excessive alcohol consumption
- lack of exercise
- obesity
- stress
- sleep apnea
Symptoms and Complications
Hypertension can occasionally cause headaches, vision problems, dizziness, or shortness of breath - but most people with hypertension have no symptoms. This is why hypertension is referred to as the "silent killer." Hypertension is usually discovered at a regular medical check-up when a doctor or nurse takes a blood pressure reading.
Making the Diagnosis
If your blood pressure is above the normal range on up to five readings (taken at different visits), a diagnosis of high blood pressure will be made. Blood pressure tends to be at its highest during exercise, physical work, or stress, and lowest during sleep. Everyone can have a temporary increase in blood pressure at one time or another, which is why it's important to take multiple readings.
If blood pressure is high, a physician will also want to know if there are any other risk factors such as high cholesterol, diabetes, inactivity, obesity, smoking, or a family history of heart disease. The more risk factors someone has, the higher the chance of getting heart disease or stroke.
A doctor might take an electrocardiogram (ECG) for a reading of the electric activity of the heart or get blood samples to see if high blood pressure has caused any organ damage.
Treatment and Prevention
The management of hypertension includes lifestyle changes and the use of medications. Proper treatment of high blood pressure can add years to a person's life. Controlling blood pressure with medications can decrease the risk of stroke and heart disease. Medications used to lower blood pressure include diuretics (e.g., hydrochlorothiazide),* beta-blockers (e.g., atenolol, metoprolol), ACE inhibitors (e.g., ramipril, enalapril, lisinopril), calcium channel blockers (e.g., nifedipine, amlodipine), and angiotensin II blockers (e.g., losartan, valsartan). People who have other risk factors especially those with diabetes or have already suffered heart damage may be started on drugs even if their blood pressure is below "officially" hypertensive levels.
In most cases, the goal of treatment is to bring down the systolic pressure to less than 140 mm Hg and the diastolic pressure to less than 90 mm Hg. For some people (such as those with diabetes or chronic kidney disease), the blood pressure should be lowered even further. A doctor will determine what is the most appropriate goal for you.
To prevent hypertension and heart disease, here are some healthy lifestyle tips:
- Stop smoking.
- Lose weight.
- Cut down on your salt consumption.
- Eat more fruits, vegetables, grains, and fibre.
- Control alcohol intake (no more than two drinks per day).
- Get regular physical activity (30 to 45 minutes of activity several days a week).
