What is high blood pressure?
High blood pressure, also called hypertension, is when the force of the blood flowing through the blood vessels is too high. 1 When blood pressure is measured, two values are recorded in millimetres of mercury (mm Hg). 2 The higher value reflects the highest pressure in the blood vessels, which is reached when the heart contracts. 2 The lower value reflects the lowest pressure in the blood vessels, which is reached just before the heart begins to contract again. 2 A blood pressure of 120/80 mm Hg, or less, is normal. 2 Persistent high blood pressure readings of over 130/80 mm Hg are labelled hypertension and usually requires medical treatment. 2,3
South Africa has one of the highest rates of high blood pressure worldwide, with 1 in 3 adults having high blood pressure. 4,5 The numbers are even higher in older adults (> 50 years) – 8 out 10 have high blood pressure. 5
What causes high blood pressure?
Most cases of high blood pressure have no cause – this is called primary hypertension. 2 Secondary hypertension results from underlying disorders such as kidney disease or hormonal disorders and certain medications. 2 Risk factors for high blood pressure include modifiable (can be changed) and nonmodifiable (cannot be changed) factors. 1
Nonmodifiable risk factors
- Age – blood vessels naturally thicken and stiffen over time, so blood pressure tends to increase with age 1
- Family history – high blood pressure often runs in families 1
- Gender – before age 55, men are more likely to develop high blood pressure. After age 55, women are more likely than men to develop high blood pressure 1
Modifiable risk factors
Unhealthy lifestyle habits can increase the risk of high blood pressure, these include: 1,2
- Unhealthy eating patterns – eating too much sodium (salt)
- Drinking too much alcohol
- Being physically inactive
- Being overweight or obese
What are the complications of high blood pressure?
It is important to regularly get your blood pressure checked because high blood pressure usually does not cause symptoms until serious complications occur. 1 Untreated or uncontrolled long-standing high blood pressure can result in the complications such as heart attacks or heart failure, strokes, dementia, kidney disease, and eye damage. 1,2
How do you manage high blood pressure?
Primary hypertension cannot be cured, but it can be controlled to prevent complications. 2 Management includes lifestyle changes and/or medications to lower blood pressure (called antihypertensives). 2
- Eat a healthy diet e.g. DASH diet – a diet high in fruits, vegetables, and whole grains with a moderate consumption of lean meats, healthy fats and low-fat dairy products and a limited intake of salt, cholesterol and saturated fats. 6 To find out more information, visit https://dashdiet.org.
- Exercise regularly – moderate to vigorous exercise 3 to 4 times per week for an average of 40 minutes per session e.g. walking, dancing, bicycling, gardening, swimming, tennis. 6
- Maintain a healthy weight – lose weight if you are overweight or obese 6
- Quit smoking 6
- Limit alcohol intake – men should have no more than 2 servings alcohol per day and women no more than 1 serving of alcohol per day 6
- Manage stress – try meditation or yoga 1,6
Medications to lower blood pressure (Antihypertensives)
When healthy lifestyle changes alone do not control or lower high blood pressure, your doctor may prescribe medicines to treat your condition. 1 Different medications work using different mechanisms, so many different treatment options are possible. 2 Most people will require two or more drugs to reach their blood pressure goal. 2
- Diuretics – flush excess sodium and water from the body, reducing the amount of fluid in the body 1
- Calcium channel blockers – stops calcium from entering the muscle cells of the heart and blood vessels and allows the blood vessels to relax 1
- Angiotensin-converting enzyme inhibitors (ACE inhibitors) – blocks production of substances in the body that narrow blood vessels 1
Angiotensin II receptor blockers (ARBs) – blocks binding of substances to receptors to prevent narrowing of blood vessels 1