High blood pressure, also known as hypertension, is not a disease, but is a risk factor for cardiovascular disease. Other risk factors for cardiovascular disease include diabetes, high cholesterol levels, obesity, smoking, family history of heart disease, age, and being male. Some of these risk factors cannot be changed; therefore it is important to modify the factors you can change in order to reduce the risk of strokes and heart attacks.

Blood pressure readings consist of two numbers: systolic and diastolic. Systolic, the higher number, is the pressure against the walls of the arteries when the heart contracts and pumps blood through the body. Diastolic pressure, the lower number, is the pressure between pumps when the heart is resting. The America Heart Association defines mild-high blood pressure as greater than 140/90mmHg (millimeters of mercury), moderate-high blood pressure as greater than 160/100 mmHg and very severe as greater than 210/120mmHg. Your blood pressure varies throughout the day. For instance, it becomes elevated when you exercise, which is normal. It is only when your blood pressure is consistently elevated that there is cause for concern.

Causes

In 90% of cases, the cause of high blood pressure is unknown. This is called essential hypertension. Some factors associated with high blood pressure include genetics, age, stress, obesity smoking, high salt diet smoking, excessive alcohol intake and a sedentary lifestyle.

Symptoms

High blood pressure usually develops slowly over many years with no noticeable symptoms. It is sometimes referred to as the 'silent killer' because of its insidious onset. The symptoms below may be caused by high blood pressure but may also have other causes. See your doctor if you experience any of the following symptoms:

• Dizzy spells
• Chest pain
• Unexplained vision changes
• Frequent headaches
• Ankle swelling

Your blood pressure has to be very high before symptoms such as dizziness, headaches or racing heartbeat appear. It is very important to check your blood pressure regularly to help prevent these symptoms from occurring.

Why Is It Harmful?

High blood pressure increases the risk of serious health problems, particularly strokes and heart attacks. Long term high blood pressure can result in the bursting of a blood vessel, which occurs most often in the brain where small arteries can develop a weak spot. The weak spot - known as an aneurysm - can burst, cause bleeding into the brain tissue, and cause a stroke.

High blood pressure can damage the delicate lining of the arteries and make it easier for cholesterol to deposit and form plaques. These plaques can break off and block the blood flow, which can cause a heart attack. High blood pressure also makes the heart work harder, which makes its walls thicker and the blood vessels that supply the heart cannot keep up. This results in chest pain from coronary artery disease.

Over the long term, high blood pressure can damage the kidneys in two ways: by damaging the small vessels in the kidney and by damaging the glomerulus's (the filter mechanism). The small blood vessels in the eye can also be affected by high blood pressure, leading to loss of vision.

Controlling High Blood Pressure

High blood pressure can be controlled through lifestyle modification and with medication. If your doctor has prescribed medication for your high blood pressure, it is very important to follow the instructions exactly, even if you feel you don't have symptoms.

Try the following tips for controlling your blood pressure:

• Maintain a healthy weight
• Avoid excess salt
• Exercise at least three times per week
• Practice stress management techniques
• Be moderate with alcohol intake
• Eat more fresh fruits and vegetables (follow the Canada Food Guide)
• Abstain from smoking
• Have your blood pressure checked regularly

Some Facts About Blood Pressure

• Regular exercise (30 minutes, 3 times per week) can lower blood pressure by about 5mmHg.
• Smoking one cigarette increases blood pressure by 5-10mmHg for 30 minutes; a pack a day smoker will increase their average daily blood pressure by 5mmHg.
• Excessive salt intake can aggravate high blood pressure by causing water retention, which makes your heart work harder than it should. The recommended salt intake is 2400mg per day; but beware: many packaged foods have high salt content and the average person unknowingly consumes 4000-6000mg daily.

If you need to check your blood pressure on a regular basis, come into one of our stores to use our automated blood pressure machine - it's fast, easy and free!

Compiled by Anastasia Shortt
Dyck's Pharmacists, Kelowna, B.C.
Edited by Megan Stiles
Last Reviewed: September 2001