Blood pressure rises and falls. When it stays elevated, you have high blood pressure or ‘hypertension’.
What is Blood Pressure?
Blood pressure is the force of the blood pushing against the walls of your arteries.1, 2 You need a certain amount of pressure in your arteries to keep the blood flowing.2
• Blood pressure is at its highest when your heart muscle contracts and pumps blood to all parts of your body – systolic blood pressure (SBP).
• Your lowest level of blood pressure is when your heart is at rest between heart beats – diastolic blood pressure (DBP).1, 2
High blood pressure can be harmful to you
Blood pressure rises and falls during the day. When it stays elevated over time, you have high blood pressure or ‘hypertension’. This can be harmful to you because it makes your heart work too hard. The high force of the blood flow can harm arteries and organs such as the heart, kidneys, brain, and eyes.2, 3
You have hypertension if your blood pressure reading is 140/90 mmHg or higher.1,4 Both the SBP and DBP numbers are important; if either of them is above the cut-off point, you have hypertension.1 For individuals aged 40 to 70 years, each increase of 20mmHg in SBP or 10mmHg in DBP doubles the risk of cardiovascular disease.5
Blood pressure goals6,7, 8
If untreated high blood pressure can cause: 1, 2, 8
- Heart failure
- Small bulges (aneurysms) in the arteries
- Kidney failure
- Atherosclerosis (hardening and narrowing of the arteries) caused by a slow build-up of plaque on the inside walls of the arteries – this can cause a heart attack, stroke or kidney failure
- Blood vessels in the eye to burst or bleed – this may cause changes in your vision and result in blindness
Causes and are you at risk?
The exact cause of high blood pressure is unknown but the following may play a role: 2
- Lack of physical activity 2
- Being overweight or obese 1, 2, 4, 6
- High alcohol consumption 2
- Too much salt in your diet 2
- Too little potassium in your diet 1
- Smoking 4, 5, 6
- Genetics – if anyone in your family has experienced high blood pressure or a stroke, you are more likely to have it 1, 2, 4, 6
- Diabetes 5, 6
- Some medications such as oral contraceptives 2
- If you are older than 55 (men) or 65 (women) 4, 5, 6
Symptoms of high blood pressure
High blood pressure is known as the silent killer because it usually has no symptoms or warning signs.1, 2 The only way to know if you have high blood pressure is to have it measured by a healthcare professional with the necessary equipment.2
About six million South Africans 15 years and older suffer from hypertension, of whom millions are not diagnosed and even more inadequately treated.1 It is usually a lifelong condition and should not be taken lightly.1 Up to 8% of men and 11% of women 30 years or older in South Africa have died from high blood pressure.1
How to control your blood pressure 1, 2, 3, 9
The Department of Health in South Africa recommends a healthy lifestyle as the best way to manage hypertension. Research shows that a healthy lifestyle will:
- Reduce your blood pressure
- Make your high blood pressure medication work more effectively
- Reduce your risk of heart disease
Basic lifestyle changes to give yourself the best chance of managing hypertension and improve your health:
- Be physically active and aim for 30 minutes of exercise a day1,2, 3, 4
- If you are overweight, lose weight and reduce your waist size2, 4
- Eat more potassium-rich fruit and vegetables such as bananas, apricots, potatoes, sweet potatoes and spinach3
- Consume less than 2400 mg of salt a day (less than one teaspoon)9
- Reduce alcohol intake2, 4
- Stop smoking – if you are a smoker, stopping smoking is the single most important step you can take to improve your heart health 2 , 4
About 6 million South Africans 15 years and older suffer from hypertension1
Will you require prescribed medication?
If your blood pressure remains high despite making changes to your lifestyle for 6-12 months, your doctor may prescribe medication.9 Commonly prescribed medications can lower blood pressure2, 6, 7 and may have protective benefits for your heart and kidneys9
High blood pressure is usually a lifelong condition and should not be taken lightly9
REFERENCES – Further Reading: 1. Steyn K. The Heart and Stroke Foundation South Africa. Heart Disease in South Africa. Media Data Document. Department of Medicine, University of Cape Town & Chronic Diseases of Lifestyle Unit, at the Medical Research Council. July 2007, p1-p30. Available from: http://www.mrc.ac.za/Hypertension/Hypertension.htm Accessed 13.06.2013. 2. Thompson L. British Heart Foundation. I’ve Got My Blood Pressure Under Control. July 2015. Available at https://www.bhf.org.uk/heart-matters-magazine/medical/high-blood-pressure-latest-news . Accessed 09.09.2015. 3. Your Guide To Lowering Your Blood Pressure With DASH. DASH Eating Plan. Lower Your Blood Pressure. U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES. National Institutes of Health. National Heart, Lung, and Blood Institute. DASH Diet. NIH Publication. 06-4082. Revised 2006. U.S. Department Of Health And Human Services. Available from: www.nhlbi.nih.gov/health/public/heart/hbp/dash/new_dash.pdf Accessed13.06.2013. 4. Mancia G, Fagard R, Narkiewicz K, Redón J, Zanchetti A, Böhm M, et al on behalf of the The Task Force for the management of arterial hypertension of the European Society of Hypertension (ESH) and of the European Society of Cardiology (ESC). 2013 ESH/ESC Guidelines for the management of arterial hypertension. J Hypertens 2013;31(7):1281-1357. 5. Chobanian AV, Bakris GL, Black HR, Cushman WC, Green LA, Izzo JL, et al. The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. The JNC 7 Report. JAMA 2003;289(19):2560-2572. 6. Seedat YK, Rayner BL, Veriava Y. South African hypertension practice guideline 2014. Cardiovasc J Africa 2014;25(6):288-294. 7. Mancia G, Laurent S, Agabiti-Rosei E, Ambrosioni E, Burnier, Caulfield MJ, et al. Reappraisal of European guidelines on hypertension management: a European Society of Hypertension Task Force document. J Hypertension 2009;27: DOI:10.1097/HJH.0b013e328333146d. 8. James PA, Oparil S, Carter BL, Cushman WC, Dennison-Himmelfarb C, Handler J, et al, on behalf of the Panel Members Appointed to the Eighth Joint National Committee (JNC 8). 2014 Evidence-Based Guideline for the Management of High Blood Pressure in Adults. JAMA 2014;311(5):507-520. 9. Seedat YK, Rayner BL. South African Hypertension Guideline 2011. S Afr Med J 2012;102(1):57-84.