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HIGH BLOOD PRESSURE SERIES · ARTICLE 1 OF 12
What is high blood pressure?
A plain-English guide for South African families.
Roughly one in three South African adults is living with high blood pressure. That is somewhere around 13 million people. About half of them have no idea they have it. The other half know — but many are not being treated, or not being treated well enough to actually bring the numbers down.
This is a quiet problem, and it is the single biggest cause of strokes and heart attacks in our country. The good news is that high blood pressure responds beautifully to small, ordinary changes — and to medication when it is needed. The first step is understanding what it actually is.
Before you read on
This is information, not medical advice. If you think you or someone you love has high blood pressure, see a clinic nurse or doctor for diagnosis and treatment. Both are free at public clinics.
What blood pressure actually is
Every time your heart beats, it squeezes a thump of blood out into a network of pipes called arteries. That blood has to push against the walls of the pipes to keep flowing. The pressure of that push is your blood pressure.
It is measured in millimetres of mercury — written as mmHg. You will see two numbers, one on top of the other, like a fraction:
120 / 80 mmHg
The top number is the pressure when your heart squeezes. The bottom number is the pressure when your heart relaxes between beats and refills.
The two numbers, explained simply
Number Real name What it means Top Systolic How hard the blood pushes against the artery walls when your heart squeezes. Bottom Diastolic How hard the blood is still pushing when your heart relaxes between beats.
Both numbers matter. A high top number is a risk on its own. A high bottom number is a risk on its own. When both are high, the risk is higher still.
What counts as normal, raised, and high
South Africa follows the same blood pressure categories as the international guidelines. They look like this:
Category Top number Bottom number Normal less than 120 and less than 80 Elevated 120 – 129 and less than 80 Stage 1 high BP 130 – 139 or 80 – 89 Stage 2 high BP 140 or more or 90 or more Crisis (call for help) 180 or more or 120 or more
One single high reading does not mean you have high blood pressure. Blood pressure goes up and down through the day — after exercise, after a coffee, when you are angry, when you are stressed. The diagnosis only happens when the numbers are high on two or three separate visits, or on a 24-hour monitor.
What it does mean, though, is that something is worth watching. The further above normal your readings are, the harder your heart and your blood vessels are working all the time, day and night, year after year.
If a reading is 180 / 120 or higher
That is a hypertensive crisis. Sit down. Rest for 5 minutes. Re-test. If it is still that high — or if you have chest pain, a bad headache, blurred vision, weakness on one side of the body, or trouble speaking — get to a clinic or hospital immediately. Call 10177 for an ambulance if you cannot get there yourself.
The silent killer problem
High blood pressure has earned the name “the silent killer” for a simple reason: most people who have it feel completely fine. There is no pain. No discomfort. No warning sign you can feel. Many South Africans only find out something is wrong after their first stroke or heart attack — and by then a lot of damage has already been done.
People sometimes say, “I would know if my BP was high — I would feel a headache, my heart would race, my face would go red.” This is one of the most dangerous myths in medicine. Most people with high BP have none of those things, almost all of the time.
If headaches, dizziness, nosebleeds or chest tightness do appear, BP has often been high for years already, and the body is starting to complain about the damage.
The only way to know your blood pressure is to measure it.
Who tends to get it
High BP is partly about how your body is built and partly about how you live. Most people who develop it have a mix of both. The main risk factors:
• Age. The risk goes up steadily after 40. By age 60, more than half of South African adults have high BP.
• Family history. If a parent or a sibling has high BP, your risk is roughly double.
• Being of African ancestry. Black South Africans develop high BP earlier, more often, and tend to need more medication to control it. Researchers are still working out exactly why.
• Salt. The average South African eats 8 – 12 grams of salt a day. The World Health Organization recommends no more than 5 grams. Most of it is hidden in bread, processed meat, stock cubes and takeaways — not the salt shaker.
• Weight. Extra weight, especially around the middle, raises BP.
• Alcohol. More than two drinks a day reliably pushes BP up.
• Smoking. Every cigarette stiffens the artery walls a little more.
• Diabetes. About two out of every three diabetics also have high BP. The two conditions amplify each other’s damage.
• Stress. Chronic, long-term stress — the kind that comes from money worries, long commutes, unsafe neighbourhoods, or a tough home life — keeps BP raised for years.
How it is diagnosed
Diagnosis is the easiest thing in medicine. A nurse straps a cuff around your upper arm, pumps it up, lets the air out, and reads two numbers. It takes about a minute, costs nothing at a public clinic, and is the single most useful health check most adults can do.
You will usually be measured at least twice, on two different visits, before a diagnosis is made. The reason is white-coat hypertension — many people’s BP goes up just because they are sitting in a clinic. Two readings, taken on different days, in different moods, give a much truer picture.
If those readings are borderline, the clinic may suggest a 24-hour ambulatory monitor — a small device you wear on your arm for a day, which takes readings every 20 to 30 minutes, including while you sleep. This is the gold standard for diagnosis.
You can also start measuring at home, with an inexpensive upper-arm monitor from a pharmacy. We will cover this in article 4 of the series, including how to measure properly, which monitor to buy, and what to do with the readings.
Where to get your BP checked — free
Any public clinic — BP checks are part of chronic care and are offered to every adult who walks in.
Most retail pharmacies (Clicks, Dis-Chem, Pick n Pay) — free BP check at the pharmacy counter, no appointment, no diagnosis but a useful screen.
Many workplaces — annual wellness days usually include a BP check, often with a nurse on site.
What high BP does if you leave it alone
Imagine a garden hose. You turn the tap on a little: water flows gently, the hose stays soft, and it lasts years. You turn the tap on hard, day and night, for years on end. The hose stiffens, the walls weaken, and eventually it bursts somewhere.
That is roughly what happens to your arteries when blood pressure is high for a long time. The walls thicken and stiffen. They get scarred. In some places they balloon outwards. In others they crack and bleed.
The places where this damage shows up first are the places where small, delicate blood vessels matter most:
• The brain — stroke. High BP is the single biggest cause of stroke in South Africa.
• The heart — heart attack and heart failure. The heart muscle has to work harder against the higher pressure, and over years it gets tired and weak.
• The kidneys — chronic kidney disease, eventually leading to dialysis in the worst cases.
• The eyes — damage to the small blood vessels in the retina, which can cause vision loss.
• The brain again — chronic high BP is now firmly linked to several forms of dementia.
We will go into detail on each of these in article 3 of the series. The point for now is that none of them are inevitable. High blood pressure responds — properly and measurably — to treatment.
The good news
High blood pressure is one of the most treatable conditions in medicine.
• It can be measured easily and for free.
• It responds to ordinary food, ordinary walking, and a little less salt.
• There are good medications. The most common ones cost almost nothing on the public sector, work within weeks, and have manageable side effects.
• Bringing BP down by even a modest amount — say, from 150 / 95 down to 130 / 85 — cuts the risk of stroke, heart attack and kidney disease dramatically. We are talking about real, life-changing risk reduction, often within two or three years of starting treatment.
High blood pressure is not a sentence. It is a manageable condition that responds to consistent, kind, ordinary care.
The bigger picture
Most people we know in South Africa either have high BP, will get it, or love someone who does. It is not unusual. It is not shameful. It is not a sign of weakness or moral failure or eating too much salt at last week’s braai.
It is the body’s response to decades of living — of carrying weight, of carrying stress, of eating food that’s higher in salt than the body was built for, of getting older. And it is, in almost every case, manageable.
The next article in this series unpacks the silent killer problem in more detail: who is most likely to have high BP without knowing, how to know if you are one of them, and the small daily decisions that make the difference between BP that is quietly damaging you and BP that is under control.
Where to get more help
Heart and Stroke Foundation South Africa — heartfoundation.co.za · 021 422 1586 — patient information, support, and a free risk calculator.
Your nearest public clinic — free BP checks, free chronic care, free medication for those who qualify.
South African Hypertension Society — hypertension.org.za — guidelines and patient resources.
Phila Today Diabetes Series — recommended companion reading for anyone with both conditions.
Phila Today High Blood Pressure Series — next: the silent killer problem — Stage 1, Stage 2, and how to know if you have it.
Phila Today · Article 1 of 12 in the High Blood Pressure Series