Blood pressure: how high is too high?

High blood pressure - or hypertension as doctors call it - may call to mind headaches, dizzy spells and a florid complexion. However, most people with it have no pain, no symptoms and many will not even know that their blood pressure is raised.

High blood pressure affects around one in three people in the UK. And in England alone more than 5.5 million people are undiagnosed. This is a worry because uncontrolled hypertension can be fatal. It dramatically increases your risk of developing heart and kidney disease, increases your risk of stroke and heart failure and is linked with a higher risk of peripheral arterial disease, and vascular dementia.

The good news is, alongside tried-and-tested methods, such as exercise, losing weight and quitting smoking, there are lots of innovative and simple ways to lower BP in the short and long term.

What causes hypertension?

In most cases the cause is unknown. However, a number of risk factors can make you more susceptible. These include:

The things you can’t do anything about

• Age – blood pressure rises with age
• Family history – genetic factors account for up to 40% of variability in blood pressure
• Gender - up to about 65 years, women tend to have a lower blood pressure however from 65 to 74 years women are more likely to have high blood pressure than men.
• Ethnicity - Black African and Black Caribbean ethnic groups are more at risk. People of South Asian origin meanwhile have a higher risk of diabetes and heart attack, so it is vital that blood pressure is well controlled.

Saga Health Insurance may be able to provide you with cover even if you already have high blood pressure (hypertension), subject to some simple health questions and an additional premium. Find out more.

The things you can do something about

• An excessively salty diet – too much salt increases blood pressure
• A sedentary lifestyle – taking little or no exercise is linked with higher blood pressure
• Smoking
• Stress and anxiety – these increase the production of adrenaline and cortisol which cause a rise in blood pressure and heart rate. Stress and anxiety can also lead to poor eating habits, smoking and drinking which pushes up hypertension risk.
• Overweight and obesity – one 10-year study of more than 200,000 people found that the more overweight a person was, the more likely they were to have high blood pressure.
• Excess alcohol – more than 14 units a week. Binge drinking is especially harmful for blood pressure.

Why is high blood pressure dangerous?

Excessive BP (usually defined as 140/90mmHg or more) can damage the cells of the arteries’ inner lining, thickening and stiffening the arteries, and forcing your heart to work harder.

This creates a host of potential problems, including stroke, kidney failure, dangerous heart rhythms, angina, heart attacks, heart failure, disease of the peripheral arteries serving the limbs and erectile dysfunction.

A large-scale analysis of randomised trials, which included 344,716 participants, found that reducing systolic BP (the top figure that reflects pressure in the arteries when the heart beats) by just 5 mm Hg reduced the risk of heart attack, stroke and heart failure by around 10%.

Remarkably this finding applied even in those previously been diagnosed with cardiovascular disease irrespective of previous diagnoses of cardiovascular disease. It also applied in people with normal or high–normal blood pressure.

High blood pressure increases your risk of:

• having a heart attack
• heart failure
• angina
• stroke

Conditions linked to high blood pressure include:

• kidney disease
• angina
• loss of vision
• sexual problems

How high is too high?

Blood pressure, the force of blood against the artery walls, is measured in millimetres of mercury (mm Hg) and recorded as two numbers:

1. Systolic pressure, the top figure , which is the pressure as the heart beats
2. Diastolic pressure, the bottom figure, which is the pressure as the heart relaxes between beats.

Blood pressure numbers and measurements explained

What do blood pressure numbers mean?

The changes in our physiology that occur as we get older lead to a rise in systolic blood pressure, a rise in the pressure in our arteries, a rise in pulse pressure and a poorer ability to respond to sudden changes in our environment. That’s why as we get older we are more likely to develop orthostatic hypotension (low blood pressure when rising from the ground or a chair) which can lead to fainting or feeling faint.

Blood pressure is considered high if it is over 140/90 but you should be concerned if it's in the upper range of normal - 130/85 - and take measures to bring it down, as the risk rises when systolic pressure goes over 110.

As we age we are also more prone to having a raised systolic pressure while the diastolic pressure remains normal - known as isolated systolic hypertension. This still needs treatment.

Why is high blood pressure dangerous?

Excessive BP (usually defined as 140/90mmHg or more) can damage the cells of the arteries’ inner lining, thickening and stiffening the arteries, and forcing your heart to work harder.

This creates a host of potential problems, including stroke, kidney failure, dangerous heart rhythms, angina, heart attacks, heart failure, disease of the peripheral arteries serving the limbs and erectile dysfunction.

A large-scale analysis of randomised trials, which included 344,716 participants, found that reducing systolic BP (the top figure that reflects pressure in the arteries when the heart beats) by just 5 mm Hg reduced the risk of heart attack, stroke and heart failure by around 10%.

Remarkably this finding applied even in those without prevalent cardiovascular disease (people with no history of strokes, heart attacks or narrowed arteries). It also applied in people with normal or high–normal blood pressure.

How do you know if you’ve got high blood pressure?

Hypertension is a silent syndrome – meaning you can’t tell you have it except by measuring it. High BP is undiagnosed in an estimated seven million Brits.

As well as having your BP checked regularly by a medical professional, experts advise getting into the habit of keeping an eye on your BP yourself.

Visit reputable online sites or your chemist to buy an affordable upper-arm cuff home monitor (look for one that’s approved by the British Hypertension Society, https://bihsoc.org/bp-monitors/for-home-use/)

Taking control of your blood pressure

Have your blood pressure checked regularly – the exact timing will depend on your BP and other risk factors so be guided by your doctor. Learn what the figures mean and if your BP is on the high side talk to your doctor about ways to lower it.

The Blood Pressure Association recommends that anyone in the upper normal range is checked annually. If you have frank hypertension your doctor will want to check it more often until it is under control.

You can also check your own blood pressure using a portable device easily available from pharmacies or online.

Saga Health Insurance offers a range of health plans which provide cover if you develop high blood pressure (hypertension). If you've already been diagnosed they can often still cover your hypertension anyway, subject to some simple health questions and an additional premium. Find out more.

Lifestyle changes

• Cut down on salt. Although things have improved in recent years most of us still consume more than the recommended daily 6g of salt, especially if we eat lots of processed and takeaway foods. Cutting salt intake by 3g a day has been estimated to reduce strokes by 13% and heart disease by 10%.
• Quit smoking if you need to.
• Aim to eat at least five portions of fruit and vegetables daily and preferably more. As well as being rich in anti-oxidants, which help protect against arterial damage, they are good sources of potassium which has been shown to help lower blood pressure.
• Drink sensibly, keep your intake to 14 units a week or less and avoid binge drinking.
• Stay active. Exercise can prevent or delay the development of hypertension and reduce high blood pressure. It will also keep your weight down, strengthen your heart, reduce levels of harmful LDL cholesterol and help boost beneficial HDL cholesterol.

10 blood pressure-lowering foods

High blood pressure treatment

While lifestyle measures can help you may need medication. The good news is that almost all hypertension can be controlled with the right medication or combination of medications. The four main types of medication are:

1. ACE inhibitors. ACE (Angiotensin-converting enzyme) inhibitors which help regulate hormones involved in blood pressure control. Names often end in ‘pril’ e.g. enalapril, lisinopril, perindopril and Ramipril.
2. Angiotensin receptor blockers (ARBs). These work in a similar way to ACE inhibitors and are usually prescribed if ACE inhibitors have caused unwanted side effects. Names often end in ‘artan’ e.g. candesartan, irbesartan, losartan, valsartan and olmesartan.
3. Calcium-channel blockers (CCBs). These encourage artery walls to relax and widen the arteries so allowing more blood to pass through. Names often end in ‘pine’ e.g. amlodipine, felodipine and nifedipine.
4. Thiazide diuretics (aka water pills). These remove excess fluid from the body placing less pressure on blood pressure walls. Names often end in ‘ide’e.g. indapamide and bendroflumethiazide.

If these don’t lower blood pressure enough other medications may be prescribed including alpha blockers, which widen and relax blood vessels; beta blockers, which slow the rate and force of the heart beat; central alpha antagonists, which work on the part of the brain that controls BP; renin inhibitors, which block production of a kidney enzyme involved in BP control; and vasodilators, which widen the blood vessels. Visit Blood Pressure UK for more information on blood pressure medication.

Common anti-hypertensive medications, such as ACE inhibitors and angiotensin-II receptor blockers, can have side effects such as headaches and dizziness, so many people stop taking them.

The 2016 SPRINT (the US-government-led Systolic Blood Pressure Intervention Trial) revealed that not only is it vital to persevere with drug therapy, but new, more intensive programmes are particularly effective.

The study compared an aggressive treatment regime that involved using as many drugs as necessary to drive systolic BP down to 120mmHg with a looser regime to reach the more usual 140mmHg. Rates of heart attack, heart failure and stroke fell by a third.

SPRINT’s final report published in 2021 concluded that among people at a high risk of heart and circulatory disease ‘targeting a systolic blood pressure of less than 120 mm Hg resulted in lower rates of major adverse cardiovascular events and lower all-cause mortality than targeting a systolic blood pressure of less than 140 mm Hg. This held true both during and after the trial.

Of course all effective treatments have side effects and in this case low blood pressure, fainting, kidney problems and imbalances in electrolytes (the minerals potassium, magnesium, sodium or calcium) were more common in those receiving intensive treatment. If you’re offered intensive treatment and are worried about this talk to your doctor.

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