High blood pressure (hypertension) is often called the "silent killer" because it rarely causes perceptible symptoms while silently damaging the arterial walls of your heart, kidneys, and brain. Understanding your blood pressure readings empowers you to take decisive preventive action.
Reading the Numbers: Systolic vs. Diastolic
Blood pressure readings are expressed as two figures measured in millimeters of mercury (mm Hg):
- Systolic Pressure (Top Number): Measures the arterial pressure when the cardiac muscle contracts and ejects blood.
- Diastolic Pressure (Bottom Number): Measures the residual arterial pressure when the heart rests between heartbeats.
Hypertension Canada Clinical Classifications
Hypertension Canada establishes clear diagnostic parameters based on standardized, repeated measurements:
- Normal: Systolic under 120 mm Hg and diastolic under 80 mm Hg.
- Elevated / High-Normal: Systolic 120–129 mm Hg and diastolic under 80 mm Hg.
- Stage 1 Hypertension: Systolic 130–139 mm Hg or diastolic 80–89 mm Hg on home monitoring (or 140–159 / 90–99 mm Hg in an office setting).
- Stage 2 Hypertension: Systolic 140 mm Hg or higher, or diastolic 90 mm Hg or higher on home monitoring (or 160+ / 100+ mm Hg in clinic).
Proper Technique for Home Blood Pressure Monitoring
To ensure valid data for your physician:
- Avoid caffeine, smoking, and vigorous exercise for 30 minutes prior to measurement.
- Sit quietly in a chair with back supported, feet flat on the floor, for 5 minutes before pressing start.
- Rest your arm on a table so the cuff is level with your heart. Use a validated, fitted upper-arm cuff (avoid wrist monitors).
- Take two readings 1 minute apart morning and evening for 7 days, recording the results in a log.
🚨 Hypertensive Urgency vs. Emergency
A reading exceeding 180/120 mm Hg requires medical attention. If severe headache, vision changes, chest pain, or shortness of breath accompany this reading, call 911 or proceed immediately to the Peter Lougheed Centre emergency department. For routine monitoring and personalized management, consult your Medi Plus family physician or call Health Link at 811.
