Unpacking Hypertension: What It Is and How to Prevent It
Hypertension, or what most people know as high blood pressure, happens when the pressure of the blood flowing through your arteries stays too high for too long. The World Health Organisation reported that nearly 1.4 billion adults worldwide aged 39-70 years had high blood pressure in 2024, or 33% of the population in that age range.
Blood pressure is recorded as two numbers. Most people have heard that the standard blood pressure levels in a healthy adult should be 120/80 mm Hg (or slightly lower). The 120 is the systolic, which is the pressure created when the heart beats and blood is being pumped out. The 80 is the diastolic, the pressure when the heart rests between beats while it’s filling with blood.
South African clinical guidelines classify sustained blood-pressure readings at or above 130/85 mm Hg as hypertension in many settings, a change introduced to encourage earlier detection and management. Just to note, low blood pressure is classified as lower than 90/60 mm Hg, this is only considered hypotension if symptomatic.
Take a look at the table below that shows the differences in blood pressure readings and when you should be concerned.
Blood Pressure Category | Systolic and Diastolic Pressure (mm Hg) |
Low | 90 systolic pressure and 60 diastolic pressure |
Normal and optimal | Below 130 systolic pressure and below 85 diastolic pressure |
High normal | 130 – 139 systolic pressure or 85 – 89 diastolic pressure |
Mild hypertension | 140 – 149 systolic pressure or 90 – 99 diastolic pressure |
Moderate hypertension | 160 – 179 systolic pressure or 100 - 109 diastolic pressure. See a doctor or GP as soon as possible. |
Hypertensive emergency | Above 180 systolic pressure or above 110 diastolic pressure. With symptoms: Treat as a medical emergency. Go to a hospital immediately. Without symptoms: Rest and recheck. If still high, seek medical attention. |
Hypertension: The Silent Killer
Hypertension is extremely common worldwide and is a leading cause of cardiovascular disease and premature death. Many people with high blood pressure are unaware of it, which is why it’s known as The Silent Killer. Regular check-ups with your GP or other healthcare providers are important to identify any risks that might not be known to you as there aren’t always obvious symptoms.
Types of Hypertension
There are two main types of hypertension, namely primary and secondary hypertension.
Primary (essential) hypertension: The most common form. It develops gradually over years and is from a mix of genetic predisposition, ageing, and environmental or lifestyle factors.
Secondary hypertension: Caused by another identifiable condition or certain medications. It can appear more suddenly and can also be reversible with successful treatment of the underlying conditions. Things that can cause secondary hypertension include thyroid problems, sleep apnoea, congenital heart defects, cough and cold medicines, birth control pills, other prescription drugs, and illegal drugs.
Factors That Contribute to Hypertension
Hypertension is usually caused by multiple factors; in rare cases it could be just one. When these multiple factors (genetics, eating habits etc.) combine, it can cause a serious problem. Here are a few of the main causes that contribute to hypertension:
High salt intake: Dietary sodium and poor eating patterns lead to fluid retention, which increases vascular resistance. Diets that are high in processed foods and saturated fats also increase your risk of cardiovascular disease. There’s strong evidence from multiple clinical studies to show reducing sodium intake has a positive effect on lowering blood pressure. There are also many ways to make sure your food is still tasty without adding extra salt.
Excess body weight: Carrying even just a few extra kilograms can put extra strain on your heart and force it to work harder to pump blood. Losing weight, even a small decrease in the numbers on the scale (not counting muscle weight), can lower your blood pressure.
Lack of exercise: Physical inactivity is a well-known risk factor that can lead to cardiovascular problems. Regular aerobic activity that gets your heart pumping improves vascular health and reduces blood pressure.
Tobacco and alcohol: Smoking damages blood vessels and raises your cardiovascular risk. Heavy alcohol use raises blood pressure, which can be damaging long-term.
Chronic stress and poor sleep: Repeated activation of stress pathways, untreated sleep apnoea, and chronic sleep restriction are linked to higher blood pressure.
Age and genetics: Blood vessels stiffen with age, but having a family history of hypertension also raises lifetime risk. Adopting a healthy lifestyle is even more important for those who have inherited risk.
What Uncontrolled Hypertension Does to the Body
Over time, persistently high blood pressure damages organs, which could lead to complications like:
Heart disease: left-ventricular hypertrophy, coronary artery disease, heart failure.
Stroke: weakened or occluded cerebral vessels raise risk of ischaemic and haemorrhagic stroke.
Kidney disease: hypertension is both a cause and a consequence of chronic kidney disease.
Vision loss: hypertensive retinopathy can impair sight.
Cognitive decline: cumulative vascular injury is associated with higher dementia risk.
Large epidemiologic reviews and guideline bodies uniformly link blood-pressure levels with cardiovascular events, and show that lowering blood pressure reduces those risks.
How to Prevent Hypertension
The strongest actions to prevent or delay hypertension are lifestyle. Here are a few practical steps to implement to prevent hypertension.
1. Eat a heart-healthy diet
Adopt a diet rich in fruits, vegetables, whole grains, legumes, lean proteins, and unsaturated fats. The Mediterranean and DASH (Dietary Approaches to Stop Hypertension) diets are backed by randomised trials and guideline recommendations for lowering blood pressure. Reduce processed foods and aim to keep sodium low (around 2,000 mg/day of sodium or 5g/day of salt).
Here are some of our favourite heart-friendly AND super tasty recipes.
Spicy Lentil and Sweet Potato Dhal
Curry and Yoghurt Marinated Chicken Skewers
Grilled Chicken Potato Salad with Spicy Herb and Pomegranate Dressing
2. Maintain a healthy weight
If you’re overweight, losing even 5–10% of your body weight reduces blood pressure enough to have a measurable impact on heart health. Weight management through diet and activity is a first-line intervention supported across guidelines.
3. Move more
Aim for at least 150 minutes/week of moderate aerobic activity, like brisk walking, or 75 minutes/week of vigorous exercise, plus muscle-strengthening twice weekly. Exercise lowers resting blood pressure and improves vascular function.
4. Stop smoking and limit alcohol
Quitting tobacco has immediate and long-term cardiovascular benefits. Also make sure your alcohol consumption is within guideline limits; in South Africa that’s defined as no more than one standard drink per day for women and two for men, though lower intake is safer for blood pressure control.
5. Improve sleep and manage stress
If you think you have sleep apnoea, it’s a good idea to chat to your doctor about a sleep study to get a confirmed diagnosis and proper treatment. You also need to manage stress and ensure you’re getting a proper night’s sleep. Try stress-reduction and good sleep hygiene strategies like journalling, meditation, no screens one hour before bedtime, breathing techniques, and cognitive behavioural therapy.
6. Check your blood pressure regularly
You can buy a home monitor at most pharmacies to self-check your blood pressure and catch any warning signs early. Follow the guidelines on approved home monitors and ensure you’re consistent with your measurements.
When measuring your blood pressure at home, make sure you take the measurement at the same time every day, while sitting down in a comfortable position. Sit still during the reading and breathe normally, ensuring the cuff is snugly in position on your upper arm, not over clothing.
For at or least half an hour before taking your measurement avoid:
- Caffeine
- Nicotine
- Alcohol
- Exercise
7. Follow medical advice and take medication when needed
When lifestyle changes aren’t enough, medications prescribed by your doctor are effective and safe for most people. Major guideline trials (including large randomised controlled trials) show that targeting lower blood-pressure goals reduces cardiovascular events, but treatment must be tailored to the individual.
Bottom line
Hypertension is common, often silent, and a leading cause of heart attack, stroke, kidney disease, and premature death, so early detection matters. Most cases are caused by lifestyle factors, combined with age and genetics. However, it’s possible to reduce your risk of hypertension with diet, exercise, weight loss, less sodium, better sleep, and giving up smoking. If lifestyle steps don’t get you to a healthy blood pressure range, medications prescribed by your doctor can help reduce your cardiovascular risk.
This content is for general information only and does not replace professional medical advice.