High Blood Pressure: The Silent Killer

In Canada, high blood pressure, or hypertension, as it is also known, is the number one risk factor for stroke, and one of the main risk factors for cardiovascular events, including heart attack. The risk of high blood pressure increases with age. One out of two people over the age of 65 (50%) have high blood pressure, and that figure climbs to 90% among people who live to be 85 or older.

What is hypertension?

Commonly referred to as “high blood pressure,” hypertension is an increase in pressure inside the arteries. It occurs when these blood vessels shrink or harden, making the heart work harder to keep blood circulating throughout the body.

In most cases, people with an average blood pressure above 140/90 (140 over 90) mm Hg are considered to have high blood pressure.

What do the numbers mean?

The first number (for example, 140) refers to the pressure in your arteries when your heart contracts and pushes blood through your arteries. This is known as systolic pressure.

The second number is the lower of the two (for example, 90), since it refers to the pressure in your arteries when your heart is resting between heartbeats. This is called diastolic pressure.

The two figures are combined to express blood pressure, which is measured in millimetres of mercury (mm Hg).

Causes of hypertension

In rare instances, hypertension is caused by another disease, for example, kidney problems, and can resolve itself once the problem is treated. In 95% of cases, however, it is impossible to pinpoint the exact cause of hypertension. In these cases, it is referred to as “essential hypertension.”

Various factors can increase the risk of high blood pressure or worsen existing high blood pressure. Some of these factors can be modified while others are beyond your control.  

Your doctor and pharmacist are there to help you identify the factors that increase your risk of high blood pressure and take measures to modify them, where possible.

Symptoms of hypertension

Hypertension has been dubbed the “silent killer” because it often comes without any signs or symptoms. In fact, many people with hypertension don’t even know they have it.

Symptoms can occur, especially if blood pressure readings are extremely high. Here are a few possible signs :

• Headaches
• Dizziness
• Light-headedness
• Palpitations
• Vision problems
• Weakness
• Tingling

If you do experience symptoms, see your doctor without delay.

Health risks and complications

Hypertension weakens the arteries and makes the heart work harder. As a result, it prematurely wears down the arterial vessels and cardiac muscle. Hypertension compromises the proper functioning of several organs and contributes to the onset of various problems:

• Heart failure
• Heart attack (myocardial infarction)
• Kidney failure
• Stroke
• Dementia
• Retinopathy (an eye disease)
• Erectile dysfunction
• Poor circulation in the legs

Treating high blood pressure effectively is essential in order to reduce the risk of complications. The health benefits of treatment are significant! According to Hypertension Canada, treating high blood pressure leads to:

• a 40% drop in the risk of stroke
• a 15% drop in the risk of heart attack
• a 50% drop in the risk of heart failure

Diagnosing hypertension

Since blood pressure varies during the day, depending on your activities and emotions, a single high blood pressure reading does not necessarily mean you suffer from hypertension.

Before your doctor diagnoses you with hypertension, they will need to take a number of blood pressure readings to get a better overall picture. They may ask you to go back to see them a few times or prescribe ambulatory blood pressure monitoring (ABPM), which allows your blood pressure to be measured over the course of a day (and night).

For most people, their blood pressure is considered high when the average pressure is above 140/90 mm Hg. Given that diabetics are at increased risk of a cardiovascular event, they are considered to have high blood pressure when their average pressure is above 130/80 mm Hg.

Among the very elderly (over the age of 80), doctors may tolerate a slightly higher systolic pressure due to the risk of complications, e.g., a fall, if blood pressure drops too low.

Treating hypertension

Treatment for hypertension consists of improving the controllable factors listed above, and taking medication.

While some people are able to control their high blood pressure simply by changing their lifestyles, most will need to take medication at some point to lower their blood pressure to an acceptable level.

The following lifestyle changes are recommended for lowering blood pressure:

• Reduce salt intake to less than 2000 mg per day (read Nutrition Facts labels to make smart choices when shopping for food)
• Aim a healthy weight and a body mass index between 18.5 and 24.9. Calculate your BMI
• Quit smoking
• Reduce alcohol consumption
• Do moderate intensity exercise on a regular basis, ideally 30 minutes most days of the week (e.g., walking or cycling)
• Reduce sources of stress

Medications to treat hypertension are called antihypertensives. There are several categories of antihypertensive agents and each type works differently to lower blood pressure. It is not unusual to have to take several antihypertensives from different categories to bring blood pressure down to an acceptable level.

It’s important to take your medication every single day, even when your pressure is fine. Antihypertensives do not cure hypertension. If you stop taking them, your blood pressure will return to dangerously high levels.

Measuring blood pressure from the comfort of your home

It is important that people with hypertension take their blood pressure regularly to ensure their treatment is working. It is worth getting an automatic blood pressure monitor to take your blood pressure at home. Blood pressure monitors are affordable and easy to use. Ask your pharmacist for help to choose the model that’s right for you.

For the readings to be useful, they need to be taken under the same conditions and frequently enough to provide an overview of the situation. Ideally the measures should be taken for seven consecutive days, for example, the week before your appointment with the doctor or pharmacist (if the pharmacy offers blood pressure monitoring services).

It is recommended that blood pressure be measured twice a day:

• In the morning (before eating and before taking your medication)
• In the evening, before going to bed (or at least two hours after eating)

Take two readings each time, at a one minute interval, i.e., four readings per day. Some devices can be programmed to automatically take two readings.

To take a reliable and accurate reading, it is important to follow a few rules when measuring your blood pressure:

Automatic blood pressure monitors can store a large number of readings and automatically calculate average values. Results can also be noted in a logbook.

When taking your blood pressure at home, your average target blood pressure readings should be less than 135/85 mm Hg (except for diabetics or the very elderly), as pressure is not influenced by the stress of being in a doctor’s office (white coat syndrome). The blood pressure goal for diabetics is an average less than 130/80 mm Hg, regardless of who takes the reading.

Pharmacy services

If you have hypertension, it is extremely important for you to get it under control. If you are having problems reaching the targets set by your health care provider, or have questions or concerns about your treatment, speak with your family pharmacist. They can help you reach your goals by giving you the right advice and suggesting changes to your drug therapy, if needed.

If you are unable to monitor your blood pressure at home, many Uniprix-affiliated pharmacies offer a blood pressure monitoring service and private follow-up consultations. Ask about these services.