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Blood pressure - know your numbers
Published on 11 September 2017 by Dr Fionnuala Barton, GP, updated on 11 September 2017
What is High Blood Pressure?
Blood Pressure literally means the pressure within your arterial blood vessels: those that carry blood away from your heart to your organs providing them with the oxygen they require to function. High Blood Pressure or “Hypertension” happens with the internal force on the walls of the arteries is higher than normal. The result is that the heart must work harder to pump blood around the body and the vessels become under strain. When pressure is persistently high it can increase risk of the vessels clogging or being damaged. In the UK, hypertension is the second biggest risk factor for premature death and disability, smoking being the first(1). It is a major risk factor for stroke and heart disease and is therefore one of the most important preventable causes of premature illness and death in developed and developing countries(2).
Why does it matter?
Recent estimates suggest that 13.4 million people in the UK have high blood pressure. That is 1 in 4 of the UK population. The number of people with undiagnosed and untreated high blood pressure is estimated to be 5.6 million (1). When pressure is high and the heart is under strain you are more at risk of many serious health problems. If you also have high levels of cholesterol in your blood, this can “fur-up” the arteries further. If these deposits or “plaques” of cholesterol are subjected to high pressure blood flow, small “clots” can break off. These clots can then become lodged in the smaller blood vessels of the heart where they cause angina and heart attacks. When they lodge in the vessels of the brain they can cause stroke and vascular dementia. High blood pressure can also contribute to kidney damage, eye problems and poor circulation. So that is 5.6 million people in the UK alone at risk of serious debilitating illness, but who are oblivious to the risk.
How do I know if I have High Blood Pressure?
The main problem with raised blood pressure is that it often has no symptoms and can easily go undetected. Thus, it is often referred to as the “silent killer” making it a priority for prevention and control. So, the best way to protect yourself is to check your reading, be aware of the risks and make the changes that matter. This is the focus of the Blood Pressure UK “Know Your Numbers” campaign which runs from 18-24 September 2017. Occasionally when blood pressure is very high it can cause symptoms of headaches, dizziness or visual disturbance. If these symptoms occur, it would be sensible to check your blood pressure and seek medical advice urgently if your reading is high.
When is Blood Pressure “High”?
Blood pressure readings consist of two numbers and is measured in millimetres of mercury (mmHg) e.g 120/80mmHg -The first (top number) is the “systolic blood pressure” – the pressure in the blood vessels when the heart muscle is contracting. -The second (bottom) number is the “diastolic blood pressure” - the pressure in the blood vessels when the heart is relaxing between each heartbeat.
High blood pressure is defined as persistently raised blood pressure of 140/90mmHg or above. It is important to note that these thresholds are lower in patients with diabetes, chronic kidney disease or previous cardiovascular events such as heart attacks or strokes, here we aim for less than 130/80mmHg.
The following chart provides a helpful summary:
What causes high blood pressure?
Primary or “essential hypertension” accounts for 95% in the UK. The underlying cause is thought to result from a genetic predisposition (non-modifiable risk factors) in addition to cumulative effects from various modifiable risk factors.
In about 5%, high blood pressure can be due to another underlying problem such as kidney or hormone problems, or even as a side effect medications taken for another condition. This is termed “secondary hypertension” and is managed by treating the underlying cause.
1% of those with essential hypertension may go on to develop accelerated or “malignant hypertension” with readings typically over 180/110mmHg. This requires emergency hospital treatment.
What can I do about High Blood Pressure?
The good news is that high blood pressure can be easy to prevent and once detected can be straightforward to treat. And it doesn’t have to involve taking pills. The crucial thing is to be aware of your blood pressure and know what to do with the reading. To keep your blood pressure healthy, consider:
Losing weight if you are overweight – blood pressure will fall with each excess Kg lost and this will have other health benefits too;
Taking regular exercise – aim for 30 minutes of activity at least 5 days per week. However, if you have raised blood pressure seek Medical advice before undertaking exercise.
Eat a healthy and varied diet – at least 5 portions (ideally 7-9) of a variety of vegetables and fruits per day; avoid excessive high-fat foods; choose lean meat; aim for 2-3 portions of fish per week and at least 1 should be “oily”; choose wholegrain foods and aim for less than 1/3 of your plate to be “starch-based”.
Reducing Salt intake – Public Health England state that excessive salt intake is one of the most important modifiable risk factors for high blood pressure. Aim for less than 5g salt per day. Approximately 2/3 of salt we eat comes from processed food e.g cereals, soups, sauces. So avoid these as much as possible.
Reduce alcohol to less than 14 units per week and have at least two alcohol-free days per week. 1 unit = 1/2pint normal strength beer or 2/3 of a small glass of wine or a single measure of spirits.
Smoking – stopping smoking will significantly reduce your risk of complications if you have high blood pressure. If you are struggling to stop smoking see your Practice Nurse or local Pharmacist who can help.
What if I need pills?
If your blood pressure is high it is important that you seek medical advice to determine what is the best course of action for you based on your overall cardiovascular risks. Many people will require medication to control blood pressure which they make the necessary lifestyle changes to improve their numbers. Most people will require medication for life. If this is the case it is very important to engage in regular follow up and monitoring and tell your doctor if you stop your medication for any reason. A recent study found that only 10% of people with diagnosed hypertension were controlled below 140/90mmHg and the most important cause of poor control was poor adherence to medication. There are many different options available and so it is important to find the one that suits you best.
In Summary Know your Numbers. Understand the Risks. Make the Changes.