What is Blood Pressure?
Blood pressure is the force that your blood exerts against the walls of your arteries as your heart pumps it around your body. It is one of the most important indicators of your cardiovascular health and is measured in millimetres of mercury (mmHg).
Every time your heart beats, it pushes blood through your arteries. The pressure during a heartbeat is called systolic pressure, and the pressure between beats — when your heart rests — is called diastolic pressure. Your blood pressure reading shows both of these numbers, written as systolic over diastolic.
Understanding Your Reading
What the Two Numbers Mean
A blood pressure reading of 120/80 mmHg is read as "120 over 80." The top number (120) is your systolic pressure — the pressure when your heart beats. The bottom number (80) is your diastolic pressure — the pressure when your heart rests between beats.
📊 Blood Pressure Categories
- Normal: Less than 120/80 mmHg
- Elevated: 120–129 systolic and less than 80 diastolic
- Stage 1 High: 130–139 systolic or 80–89 diastolic
- Stage 2 High: 140+ systolic or 90+ diastolic
- Hypertensive Crisis: 180+ systolic and/or 120+ diastolic — seek emergency care immediately
Why Blood Pressure Matters
High blood pressure, known as hypertension, is often called the "silent killer" because it typically has no symptoms until serious damage has already occurred. Over time, uncontrolled high blood pressure can damage your arteries, heart, kidneys, eyes, and brain.
Low blood pressure (hypotension) — generally below 90/60 mmHg — can cause dizziness, fainting, and in severe cases can be life-threatening. It is important to understand your readings in context with your doctor.
When to Measure Your Blood Pressure
For the most accurate reading, measure your blood pressure when you are relaxed and have not exercised, eaten, or consumed caffeine in the last 30 minutes. Sit quietly for five minutes before taking the reading, with your arm at heart level and your feet flat on the floor.
💡 Tip: Take your blood pressure at the same time each day and keep a record of your readings. This helps your doctor identify patterns and adjust your care accordingly.
Risk Factors for High Blood Pressure
- Family history of hypertension
- Being overweight or obese
- Lack of physical activity
- High sodium (salt) diet
- Excessive alcohol consumption
- Smoking or tobacco use
- Chronic stress
- Older age
- Conditions such as diabetes or kidney disease
When to See a Doctor
If your blood pressure consistently reads 130/80 mmHg or higher, speak with your doctor. If you ever experience a reading of 180/120 mmHg or higher alongside symptoms such as chest pain, shortness of breath, or sudden severe headache, seek emergency medical care immediately.
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