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The Silent Threat: Why High Blood Pressure is More Dangerous Than You Think
Updated: 8 hours ago
An estimated 1.4 billion adults aged 30 to 79 years worldwide had high blood pressure in 2024, representing 33% of the population in this age range. Astonishingly, around 600 million adults with high blood pressure (44%) are completely unaware that they have the condition.
In this guide we'll explore:
What is High Blood Pressure?
So what does high blood pressure mean exactly, and what’s its significance?
When your heart pumps blood around the body, the blood circulates through all your blood vessels. The strength of the blood flow is called the blood pressure. If the strength of this flow is too high, then it can cause damage to both the heart muscle and blood vessels.
The high pressure in the circulatory system can cause microscopic tears in the blood vessels that can lead to atherosclerosis (formation of plaques in the arterial wall), or arteriosclerosis (hardening of the arteries) and if the high blood pressure is not treated and is prolonged, the heart muscle thickens abnormally with loss of function.
All of these microscopic changes in your body often occur without you having any symptoms, and left untreated, it can have catastrophic consequences such as:
Heart failure from damage to the heart
Angina and/or a heart attack – due to narrowing of the blood vessels supplying the heart
Stroke - caused by a blockage or a tear in the blood vessels supplying your brain
Kidney failure
What's a Normal Blood Pressure Reading?
A blood pressure reading has two numbers, written like, for example 120/80 mmHg (voiced aloud as "120 over 80"). The mmHg stands for millimetres of mercury, units that measure pressure.
The top number (systolic BP) is the pressure in your arteries when your heart beats and pushes blood out.
The bottom number (diastolic BP) is the pressure when your heart relaxes between beats.
For most adults, a healthy reading is between 90/60 and 120/80 mmHg. Above this, the risk to your heart, brain, kidneys and eyes starts to rise, often without any symptoms at all.
Category | Reading (mmHg) | What it means |
Low | Below 90/60 | Usually harmless, but see a doctor if you feel dizzy or faint |
Healthy | 90/60 to 120/80 | Keep up healthy habits |
At Risk | 120/80 to 139/89 | Not hypertension yet, but a warning sign. Lifestyle changes can help |
Stage 1 Hypertension | 140/90 to 159/99 | High blood pressure. Speak to a clinician about lifestyle changes and whether treatment is needed |
Stage 2 Hypertension | 160/100 to 179/119 | Treatment is usually recommended. Book a review soon |
Severe Hypertension | 180/120 or above | Needs same-day medical assessment |
Based on NICE guideline NG136 and NHS guidance. For educational purposes only, please consult a doctor.
But here’s the crucial thing about even small increases in blood pressure. In a landmark study in The Lancet, a 2 mmHg rise in your blood pressure increases the risk of stroke by 10%, and the risk of ischaemic heart disease (angina or heart attack) increased by 7%. And if you don't keep an eye on your blood pressure, a 20 mmHg increase in your systolic BP (or 10 mmHg in your diastolic BP) doubles your risk of death, stroke or a heart attack.
What are the Symptoms of High Blood Pressure?
High blood pressure or hypertension as it's often called, is very common. Around one third of the UK adult population suffer from high blood pressure, but because it often doesn't have any symptoms, many are not aware of it.
If you get symptoms, these can include:
Feeling dizzy
Headaches
Chest pain
Blurred vision
Nose bleeds
But remember, you won't always have these symptoms.
How Do You Feel When Your Blood Pressure is High?
You might also experience other unusual symptoms such as:
Anxiety
Confusion
Buzzing in the ears
Nausea and vomiting
What Causes High Blood Pressure?
Factors that increase your risk of high blood pressure include:
Diabetes
Being overweight or obese
Family history
Lack of exercise, a sedentary lifestyle
Smoking
Alcohol
There are also numerous other less common causes, so it's no wonder that one in four adults suffer from high blood pressure.
How Often Should I Check my Blood Pressure?
This all depends on the circumstances such as risk factors, age, etc. Here is a summary based on the UK's NICE guidelines that's been adapted by myself. Please note these are my recommendations as a consultant physician and is for general guidance only. It may not apply to your own specific situation.
Clinical Situation | Recommendation |
<40 yrs, no risk factors and normal blood pressure | Once every 1- 3 years |
≥ 40 yrs, other risk factors eg diabetes, kidney disease, family history, obesity | At least every year |
Ethnicity: South Asian, Afro-Caribbean | At least every year |
High normal reading 130-139/85-89 | At least every year |
Diagnosing or monitoring treatment | 2 x day for 7 days |
On treatment and controlled blood pressure | At each treatment review and annually |
Women: Combined oral contraceptive pill | Before treatment, 3 month review and annually |
Women: Pregnancy | At every antenatal visit |
How do you Measure Your Blood Pressure?
Your blood pressure can easily be checked by automatic machines these days. It can be done anywhere but you should ensure that you:
I have rested for at least 30 minutes
Ideally check at the same time each day
Avoid tobacco, drugs and alcohol for at least 30 minutes before checking
Where can you Measure Your Blood Pressure?
You can get your blood pressure checked in the comfort of your own home with your own blood pressure monitor or if you prefer someone else to do it, the options are;
Your GP
DIY – buy your own blood pressure monitor
Health Klinix – You can get a free blood pressure check as part of our membership scheme or we’re very happy to check your blood pressure for a small charge and if it’s elevated, our specialist consultant physicians can advise you on any further investigations and management.
Pharmacists
How to Prevent High Blood Pressure
As we've already discussed, people are often unaware that they have high blood pressure and this can lead to organ damage, or heart attacks.
So prevention is key.
Some people are at even higher risk of high blood pressure because
it runs in their family
of their ethnicity (South Asians and Afro-Caribbeans)
You can't change your parents (as much as some of us may wish to do so) but you can modify your lifestyle and significantly reduce your risk of developing hypertension.
With this in mind, you can now take steps to a healthier lifestyle.
Diet
We all live in a world full of processed foods like crisps, packaged meats, ready meals and breakfast cereals, all containing more salt than we should be consuming. The problem is that salt is a big culprit for raising your blood pressure. The UK government recommend no more than 6 grams in total per day, that's just one level teaspoon!
You can improve your diet by:
Reduce your salt intake to maximum of 1 teaspoon a day (in all your food!)
Cut down on processed food eg ham, bacon, ready-made burgers
Eat less saturated fats eg biscuits, chocolates, palm oil, butter, ghee, savoury snacks
Exercise
Regular exercise has been shown to reduce your blood pressure. Ideally you should do high intensity interval training (HIIT) for at least 40 minutes a day three times a week.
Examples include:
Cycling
Running
Skipping
Rowing
Swimming
If all of these are too energetic then simply walking around your local neighbourhood, climbing the stairs, catching the bus instead of driving, or even standing at your desk will all help too. Still can’t master it?...Here are 8 simple steps to make exercise work for you.
Alcohol
Alcohol can also raise your blood pressure. If you drink more than 14 units of alcohol per week (equivalent of 6 pints of 4% beer or 6 glasses of a medium sized glass of wine) then you need to cut down, but you don't need to stop completely. There are lots of useful ways you can do this and sometimes it's best to do a little at a time. Here are some useful tips on cutting down on alcohol.
Smoking
As well as causing atherosclerosis, a condition where your arteries are clogged up with fatty material and plaques, smoking is also a big cause of high blood pressure. By stopping smoking, you'll not only reduce your blood pressure, but there will be multiple other health benefits too such as reducing the risk of cancer, heart attacks, strokes and dementia.
Stress
This can be a big one. In our busy and hurried world, we can all get stressed occasionally.
Stress and anxiety can lead to high blood pressure by increasing your ‘fight’ or ‘flight’ hormones such as adrenaline. This directly increases your blood pressure, but only lasts for a short while. Continual stress and anxiety can lead to bad habits such as binge eating, smoking and drinking excessive alcohol, all of which can lead to high blood pressure and other ill health.
In our modern day fast-paced lives, we can't always change everything in our environment but we can manage it. If you want to know more, we’ve written a detailed article on coping with stress.
Sleep
Experts recommend that you should get 7 to 9 hours of sleep every night. Getting 6 hours or less is bad for your health and increases the risk of heart disease, strokes and can, of course - you’ve guessed it - raise your blood pressure. Sleep regulates hormones that are needed to control stress and metabolism and so not getting enough sleep disrupts this and can cause hormonal imbalances leading to high blood pressure.
Another important cause of high blood pressure is obstructive sleep apnoea. This occurs when your airways are obstructed during sleep, leading to periods of laboured breathing and even short spells when you stop breathing altogether. Your sleep is consequently light and disturbed. People who are overweight and snore are at risk of obstructive sleep apnoea. If you think you might be affected, speak to your family doctor.
How to Reduce High Blood Pressure
So you've been told you've got high blood pressure by your doctor. But do you have to take medication?
Well, not necessarily.
We've already discussed how to prevent blood pressure already and these lifestyle changes are also ways to treat high blood pressure before any medications. If you have mild hypertension, modifying lifestyle factors like reducing your salt intake, increasing exercise, stopping smoking and reducing alcohol etc can control your blood pressure without any medication.
However, in some people, medications may be necessary, especially in those with Stage 2 hypertension (blood pressure 160/100 or greater), or if you already have evidence of organ damage.
Types of medications to reduce high pressure include:
Beta blockers e.g. Bisoprolol
Angiotensin converting enzyme inhibitors e.g. Lisinopril
Calcium blockers e.g. Amlodipine
Frequently Asked Questions
What is hypertension?
This is the strength of blood flow around your body. Please see ‘What is high blood pressure’ above.
What is normal blood pressure by age?
A normal blood pressure usually lies between 90/60 and 120/80. We would usually consider treatment when your blood pressure consistently rises to 140/90 or above. However, if you're more than 80 years of age, treatment may be considered if the blood pressure is 150/90 or higher according to NICE guidelines.
Can anxiety cause high blood pressure?
Absolutely, especially if it's sustained and prolonged. See under ‘Stress’ above.
How long can I survive with high blood pressure?
Survival is dependent on many factors such as the stage of hypertension, age, organ damage, etc. However, we know that a 20 mmHg rise in your systolic BP or a 10 mmHg rise of your diastolic BP, doubles your risk of death from a stroke or a heart attack.
References
Written by:
Consultant in Infectious Diseases and Travel Medicine
MBBS, MRCP(UK), DTM&H, MRCGP, DCH, DRCOG, DFFP
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