Blood Pressure: Understanding Your Numbers and Knowing When to See a Doctor

Nearly one in four Quebecers suffers from high blood pressure. Half of them don't know it yet (National Public Health Institute of Quebec, 2022). This is not a matter of neglect. It's a matter of absent symptoms. Blood pressure can rise for years without the person feeling anything, while the arteries, heart, kidneys, and brain undergo silent and continuous pressure.

It's for this reason that it's sometimes called the silent killer. And it's for this reason that regularly measuring blood pressure is one of the most useful preventive actions a person can take.

What the numbers mean

Blood pressure is measured in millimeters of mercury (mmHg) and is expressed as two numbers. The first, systolic pressure, corresponds to the pressure exerted on the arterial walls when the heart contracts. The second, diastolic pressure, reflects this same pressure when the heart relaxes between beats.

A blood pressure considered normal in adults is around 120/80 mmHg. Between 130/80 and 139/89 mmHg, we talk about stage 1 hypertension according to the American Heart Association criteria, although thresholds vary slightly according to Canadian guidelines. From 140/90 mmHg onwards, hypertension is clearly established and requires a full medical evaluation (Hypertension Canada, 2023).

A blood pressure below 90/60 mmHg may indicate hypotension, which carries its own risks, including dizziness and falls, especially in older adults.

These thresholds are benchmarks. A single high reading is not enough to make a diagnosis. Blood pressure naturally varies throughout the day, depending on physical activity, stress, body position, and even meal times. It is the trend over several measurements, under similar conditions, that allows the doctor or nurse practitioner to make a pronouncement.

Why hypertension goes unnoticed

The vast majority of people with high blood pressure feel nothing in particular. No pain, no alarm signal, no distinctive fatigue. Some people describe headaches at the end of the day, ringing in their ears, or slightly blurred vision during very high blood pressure spikes, but these signs are rare and non-specific. They often appear at dangerous pressure levels, where damage is already occurring.

This is precisely the mechanism that makes hypertension so concerning. Chronically high blood pressure forces the heart to work harder, gradually stiffens arterial walls, and weakens small renal and cerebral vessels. The result, if not intercepted, can be a heart attack, stroke, kidney failure, or heart failure. All these complications can occur without the person ever experiencing a single warning sign.

Factors that cause pressure to rise

Some factors are modifiable, while others are not. Among those that can be influenced, diet plays a central role. High sodium intake, abundant in processed foods, cured meats, and ready-made meals, is one of the most well-documented dietary factors in hypertension literature. Sedentary lifestyle, abdominal overweight, regular alcohol consumption, and smoking also contribute significantly.

Chronic stress deserves special mention. Its effect on blood pressure is complex and mediated by several hormonal mechanisms, notably prolonged activation of the sympathetic system and cortisol secretion. Occasional stress causes a temporary rise in blood pressure, which is normal. Chronic stress maintains a baseline elevation that eventually becomes structural.

When it comes to non-modifiable factors, age is the most significant. Arterial stiffness naturally increases over time, which explains why the risk of hypertension rises sharply after age 55 in men and after age 65 in women. Family history also plays a role, as do certain ethnic origins; people of African descent statistically have a higher risk and often more severe hypertension (Hypertension Canada, 2023).

How is measurement done in the clinic?

Blood pressure measurement in a clinic is taken with a arm blood pressure monitor under standardized conditions: seated position, arm at heart level, after a few minutes of rest. The person should not have consumed coffee or tobacco within 30 minutes prior to the measurement, and should not have engaged in intense physical activity within the hour.

A high reading during an initial visit may reflect what is known as "white coat hypertension," an anxiety reaction related to the medical environment. To distinguish between actual hypertension and a situational reaction, the doctor may recommend 24-hour ambulatory blood pressure monitoring using a portable device, or repeated measurements at home under neutral conditions.

Frequently Asked Questions About Blood Pressure

Is it possible to have high blood pressure without ever having had any health problems?
Yes. It's even the most frequent situation. High blood pressure progresses for years without symptoms. Health problems often appear later, in the form of cardiovascular or kidney complications, if the condition is not managed.

Does blood pressure normally fluctuate throughout the day?
Yes. Blood pressure is naturally lower during sleep and increases upon waking. It also varies with physical activity, emotions, and diet. It's the average over several measurements under comparable conditions that matters, not a single isolated reading.

Is hypertension hereditary?
Family history increases the risk, but it doesn't guarantee that the condition will develop. Lifestyle habits play a determining role, even in people who are genetically predisposed.

What age should one start monitoring their blood pressure?
The Canadian Cardiovascular Society recommends regular measurement starting in adulthood, and at least once a year from age 40 or as soon as risk factors are present.

Can hypertension be controlled without medication?
In cases of mild to moderate hypertension, lifestyle modifications may be sufficient to bring blood pressure back to acceptable levels. For more severe or persistent forms, medication is usually necessary. This decision rests with the attending physician, who evaluates the entire clinical picture.

When to consult a healthcare professional

If you haven't had your blood pressure checked in over a year, have a family history of high blood pressure, cardiovascular disease, or stroke, or are over 40 without regular medical check-ups, you should consult a doctor. Blood pressure measurement takes two minutes. What it reveals can change a lot.

A doctor or a specialized nurse practitioner can assess your blood pressure, analyze associated risk factors, and propose appropriate follow-up care. This assessment does not require a designated family doctor. An in-person or teleconsultation at one of our Omicron Clinic in Quebec allows for immediate access.

 

Medical consultation | Clinique Omicron