High Blood Pressure: The Silent Condition You Need to Know About

What Is Blood Pressure and What Do the Numbers Mean

Blood pressure is the force your blood exerts against the walls of your arteries as your heart pumps. It is measured in two numbers: systolic pressure (the top number, when your heart contracts) and diastolic pressure (the bottom number, when your heart rests between beats). Both are measured in millimetres of mercury, written as mmHg.

A reading of around 120/80 mmHg is generally considered optimal for adults. Blood pressure is classified as elevated when the systolic reading is consistently between 120 and 129. Stage 1 hypertension starts at 130/80 mmHg, and stage 2 at 140/90 mmHg or above. A single high reading does not confirm hypertension - blood pressure naturally varies throughout the day and rises with stress, caffeine, and physical activity. A diagnosis is based on consistently elevated readings over time.

Why It Matters So Much

Sustained high blood pressure puts constant strain on your arteries and heart. Over years, this damage accumulates quietly. The consequences can be serious: heart attack, stroke, heart failure, kidney disease, and vision problems are all linked to poorly controlled hypertension. Globally, high blood pressure is the leading risk factor for cardiovascular disease and premature death. In Australia, it affects approximately one in three adults - and of those, many are undiagnosed or inadequately treated.

The reason it is so often called a silent killer is straightforward: most people with high blood pressure feel completely normal. There are no pain signals, no obvious warning signs in day-to-day life. By the time symptoms appear - such as headaches, blurred vision, or shortness of breath - blood pressure may already be severely elevated or damage may have been occurring for years.

Who Is Most at Risk

While anyone can develop hypertension, several factors increase the risk:

• Age - blood pressure tends to rise as we get older, and hypertension becomes increasingly common after 40
• Family history of high blood pressure or cardiovascular disease
• Being overweight or obese
• A diet high in sodium (salt) and low in potassium
• Physical inactivity
• Smoking and heavy alcohol use
• Chronic stress
• Certain medical conditions, including kidney disease, diabetes, and sleep apnoea
• Some medications, including certain contraceptive pills, anti-inflammatory drugs, and decongestants

People of South Asian, African, and Aboriginal or Torres Strait Islander backgrounds are at higher risk of developing hypertension at a younger age, and the consequences tend to be more severe. This makes regular checking especially important for these groups.

How It Is Diagnosed

Diagnosis is straightforward - it requires a blood pressure cuff and a few readings over time. I recommend all adults have their blood pressure checked at least every two years if it is normal, and more frequently if they have risk factors. In some cases I ask patients to monitor their blood pressure at home using a validated home device, which can give a more accurate picture than a single clinic reading, particularly for people who experience white coat hypertension (blood pressure that rises in medical settings).

Once hypertension is confirmed, I typically arrange further tests - including blood tests checking kidney function, cholesterol, and blood sugar, as well as an ECG - to assess overall cardiovascular risk and rule out secondary causes.

Treatment: Lifestyle First

For many people with mildly elevated blood pressure, lifestyle changes can bring readings back into a healthy range without medication. The evidence for these approaches is strong:

• Reducing sodium intake - cutting back on processed foods, takeaway, and added salt can lower systolic pressure meaningfully
• Regular aerobic exercise - 30 minutes of moderate activity most days has a significant and well-documented blood pressure lowering effect
• Achieving a healthy weight - even modest weight loss reduces blood pressure in people who are overweight
• Limiting alcohol - drinking within the recommended guidelines (no more than 10 standard drinks per week) helps
• Quitting smoking - smoking raises blood pressure acutely and damages blood vessels long term
• Managing stress - chronic stress contributes to elevated blood pressure; regular relaxation practices and adequate sleep matter

When Medication Is Needed

Lifestyle changes alone are not always enough, particularly for people with stage 2 hypertension or those with additional cardiovascular risk factors such as diabetes or kidney disease. In these situations, medication is an important and effective part of management. Several classes of blood pressure medications are available - ACE inhibitors, ARBs, calcium channel blockers, and diuretics among them - and the choice depends on the individual's overall health profile, other conditions, and tolerability. Most people need only one or two medications to achieve good control, and side effects are generally manageable.

Taking blood pressure medication consistently matters. Blood pressure control is a long-term commitment, and stopping medication because readings look good on the day is a common mistake - levels typically rise again once medication is ceased.

When to Come In

If you have not had your blood pressure checked recently, booking in for a quick check is a sensible step at any age, particularly if you have any of the risk factors mentioned above. If you have already been diagnosed with hypertension and are not sure whether your current management is optimised, it is worth reviewing. Good blood pressure control significantly reduces the risk of heart attack and stroke - it is one of the most impactful things you can do for your long-term health.