What causes high blood pressure? Common causes and risk factors
In most adults, high blood pressure has no single cause. It builds up over years from a mix of everyday factors such as salt intake, body weight, activity, alcohol, stress, age and family history. A smaller group have an underlying kidney or hormonal cause that their GP can look for.
Key takeaways
- Most high blood pressure comes from several overlapping factors, not one thing.
- Salt, extra weight, low activity, alcohol, ongoing stress and poor sleep all push readings up.
- Age and family history matter, but they are not a sentence: daily habits still make a real difference.
- Sometimes a kidney, hormonal or medicine-related cause sits behind it, and your GP can check for that.
- Understanding your own risk factors makes it easier to choose the changes worth making first.
What actually causes high blood pressure?
In most adults, high blood pressure develops slowly from a combination of lifestyle, age and inherited tendencies. Doctors call this primary or essential hypertension, and it accounts for the large majority of cases.
A smaller group of people have secondary high blood pressure, where another condition or a medicine pushes the numbers up. That is why a good GP visit includes questions about your family, your medicines and your general health, not just a quick cuff reading.
The good news is that many of the factors below are within your reach. You do not need to change everything at once. Knowing which ones apply to you shows you where to start.
Does too much salt raise blood pressure?
Yes, for many people a high salt intake is one of the biggest contributors. Sodium makes the body hold on to water, which raises the volume of blood in your arteries and the pressure inside them.
In South Africa, much of our salt comes from foods that do not taste very salty. Bread, processed meats such as polony, viennas and bacon, stock cubes and soup powders, packet sauces, instant noodles, chips and takeaway meals add up quickly across a day.
Salt added at the table and in the pot matters too, especially when it is paired with stock cubes. Reading labels for sodium and tasting your food before you salt it are two small habits that make a difference over months.
- Bread and rolls, which are a daily staple for many households
- Processed and preserved meats, including polony, viennas, bacon and biltong
- Stock cubes, soup powders, spice mixes and instant gravy
- Packet snacks, chips and takeaway meals
- Tinned vegetables, fish and baked beans in salty sauce
How do body weight and inactivity affect blood pressure?
Carrying extra weight, especially around the middle, makes the heart work harder to supply the body with blood. It is also linked with changes in hormones and in how the body handles salt, which can lift blood pressure over time.
Being inactive adds to the load. A heart that is trained by regular walking, cycling or dancing generally pumps more efficiently, so each beat takes less effort. A sedentary day with long hours at a desk, in a taxi or in front of the television does the opposite.
You do not need a gym. Brisk walking around the neighbourhood, taking the stairs, gardening and playing with the children all count. Small, repeated efforts matter more than occasional heroic ones.
Do alcohol and smoking raise blood pressure?
Regular heavy drinking is a well-known contributor to higher readings, and binge drinking at weekends can make pressure swing sharply. Alcohol also adds calories, which can push up body weight.
Smoking does not cause a lasting rise in the resting reading in the same way, but each cigarette raises blood pressure and heart rate for a short time, and it damages artery walls. Over the years that combination adds to your cardiovascular risk.
If you want to cut down, ask your GP or pharmacist about support. Many people find that small, steady steps are easier to keep up than dramatic overnight changes.
Can stress and poor sleep cause high blood pressure?
Stress raises blood pressure in the moment, and long periods of pressure at work, money worries or caring for family can keep it elevated. Stress also nudges people towards habits that lift pressure further, such as more salty takeaways, more alcohol, less movement and poorer sleep.
Sleep matters in its own right. Short or broken sleep keeps the body in a state of alert, and loud snoring with pauses in breathing at night, known as sleep apnoea, is linked with higher blood pressure. If your partner notices this, mention it to your GP.
Load shedding, long commutes and shift work all disturb sleep in many South African households. A consistent bedtime, a dark, cool room and switching off screens before bed are practical places to start.
What role do age and family history play?
Blood pressure tends to rise with age because arteries gradually lose some of their flexibility. That is why a check at 45 and beyond is a sensible routine, even if you feel well.
Family history counts too. If a parent or sibling has high blood pressure, your own risk is higher, and you may notice readings creeping up earlier than for others. Ancestry plays a part as well, since high blood pressure is common in many South African communities.
None of this is a destiny. People with a strong family history who keep their weight in check, move often, limit salt and alcohol, and have regular checks are well placed to keep their readings in a healthy range.
Could a kidney problem, hormones or a medicine be behind it?
Sometimes. The kidneys help control blood pressure, so kidney conditions can push readings up, and high blood pressure can in turn strain the kidneys. Hormonal conditions, such as an overactive adrenal or thyroid gland, are other possible causes, as are narrowed arteries to the kidneys.
Certain medicines can also raise blood pressure. These include some anti-inflammatory pain tablets, decongestants in cold and flu remedies, some contraceptives and stimulant medicines. Tell your GP or pharmacist about everything you take, including over-the-counter and traditional remedies.
A GP may suggest a few simple tests if your pressure is high at a young age, rises suddenly or does not respond as expected to treatment. These are routine checks and nothing to worry about in advance.
What can I do about the causes I can change?
Pick one or two changes and keep them going. Reducing the salt in your cooking, walking for 30 minutes most days and cutting down on alcohol are among the most useful places to begin.
Measure your blood pressure regularly so you can see what is working. Our guide on how to lower blood pressure naturally walks through practical steps, and the normal blood pressure reading guide shows you how to measure properly at home.
If you have already been prescribed blood pressure medicine, keep taking it as directed. Lifestyle changes work alongside it and never replace it unless your GP says so.
Frequently asked questions
What is the most common cause of high blood pressure?
There is rarely one single cause. In most adults it develops from a combination of factors, including salt intake, body weight, low activity, alcohol, stress, age and family history. Your GP can help you work out which ones apply to you.
Can young people get high blood pressure?
Yes. Weight, salt, inactivity, family history and some medicines can raise blood pressure in younger adults too. Because it often causes no symptoms, a periodic check is a good idea at any age, especially if it runs in your family.
Does drinking a lot of coffee cause high blood pressure?
Caffeine can raise blood pressure for a short while, especially in people who rarely drink it. For many people moderate amounts are fine. If your readings run high, avoid coffee for 30 minutes before measuring and ask your GP about your intake.
Is high blood pressure hereditary?
Family history raises your risk, but it does not decide the outcome. Habits such as staying active, eating less salt and keeping a healthy weight still influence your readings, and regular checks help you catch changes early.
Can stress alone cause permanent high blood pressure?
Stress raises blood pressure temporarily and can contribute to long-term changes when combined with other factors such as poor sleep, alcohol or inactivity. Finding practical ways to unwind is a sensible part of any blood pressure routine.
Can painkillers or cold remedies raise blood pressure?
Some can, including certain anti-inflammatory tablets and decongestants. Ask your pharmacist which over-the-counter products suit you, particularly if you already have high blood pressure or take blood pressure tablets.
