High blood pressure

What is high blood pressure?

When we talk about blood pressure, we are talking about the measure of force your heart uses to pump blood around your body. This measurement tells you whether your blood pressure is low, normal or high. According to the British Heart Foundation, it is estimated that 16 million people in the UK have high blood pressure, but nearly 5 million people are unaware that they have it.

A number of different factors can increase your risk of developing high blood pressure. This can include smoking, drinking too much alcohol, not getting enough exercise, or being overweight. Without treatment, high blood pressure can lead to developing long-term, serious health conditions such as coronary heart disease, kidney disease, heart attack, or stroke.

Low blood pressure is much less common. It can be caused by other underlying conditions, such as dehydration, heart failure, or pregnancy. It can also be a side effect of some medications. 

Managing high blood pressure can help reduce your risk of serious health conditions, including heart attack, heart failure, stroke, vascular dementia and kidney disease.

Measuring your blood pressure

A blood pressure reading consists of two measurements. The first is systolic pressure – the pressure when your heart pumps blood around your body. The second is diastolic pressure – the pressure when your heart rests between beats.

Blood pressure is measured in millimetres of mercury (mmHg), and the reading is given as two numbers. The first number is your systolic reading and the second is your diastolic reading. For example, a systolic reading of 120mmHg and a diastolic reading of 80mmHg would be written as 120/80.

Blood pressure can be measured using a manual or automatic monitor. A cuff is placed around your upper arm and inflated before slowly being released to measure your blood pressure. For an accurate reading, you should be seated with your legs uncrossed and your back supported.

If your blood pressure is consistently high, your GP may recommend further monitoring at home or over 24 hours to confirm whether you have high blood pressure (hypertension).

Symptoms of high blood pressure

High blood pressure is very common. It is often referred to as the 'silent killer' because it rarely has any noticeable symptoms. If high blood pressure is left untreated, it can lead to serious health conditions.

In extreme cases and when blood pressure is very high, there can be noticeable symptoms, including headaches, blurred vision, and chest pain. The only way to find out if you have high blood pressure is to get your blood pressure checked. If you are at risk of high blood pressure, you may need closer monitoring. You may also be advised to take preventative measures to reduce your risk of hypertension.

If you have symptoms you are worried could be caused by high blood pressure, including often having headaches or blurred vision, chest pain that comes and goes, or other symptoms you are worried may be caused by high blood pressure, speak to your GP or call 111.

Who is at risk of high blood pressure?

The risk of having high blood pressure increases as you get older. If you are aged 40 or over and haven't had your blood pressure checked for over 5 years, the NHS recommends getting your blood pressure checked at your GP surgery or pharmacy. 

As well as age, there are other risk factors – these include:

• having close relatives with high blood pressure
• ethnicity (Black African, Black Caribbean, and people of South Asian ethnic background may have increased risk)
• having an unhealthy diet
• smoking
• being overweight
• drinking too much alcohol
• feeling stressed over a long period of time.

Preventing high blood pressure

To help prevent hypertension, there are many lifestyle changes you can make. It’s recommended that you eat healthily, maintain a healthy weight, exercise regularly, drink in moderation (or stop drinking alcohol), and stop smoking. You should drink no more than 14 units of alcohol a week, spread over at least three days. 

Reducing the amount of salt you consume (ideally 6g or less – the equivalent of a teaspoon) and increasing the number of fruits and vegetables (at least five portions a day) that you eat is also recommended. Eating a healthier, more balanced diet can be a big help. Having plenty of fibre (wholegrain rice, bread, and pasta) can also help to lower blood pressure.

High blood pressure and pregnancy

For pregnant women, having blood pressure checked regularly is essential – even if it isn't high to begin with. Some women can develop gestational hypertension. Usually high blood pressure doesn't make you feel unwell, but it can be serious if you are pregnant. Your midwife should check your blood pressure during all of your appointments. If you have a history of high blood pressure (chronic hypertension), you should be referred to a specialist. They will discuss the risks and benefits of treatment. 

It's important that your blood pressure is monitored throughout your pregnancy to make sure it isn't affecting the growth of your baby and to check for pre-eclampsia. 

Gentle exercise each day and a healthy, balanced diet can help reduce blood pressure. 

What causes high blood pressure?

In around 90-95% of cases, the exact cause of high blood pressure is unknown. However, the risk factors described above are known to increase your chance of developing the condition. In the remaining 5-10% of cases, the cause of high blood pressure can be linked to a condition or specific cause. This is known as secondary hypertension.

Common causes of secondary hypertension include:

• kidney disease
• hormonal disorders
• obstructive sleep apnoea
• excessive alcohol or drug use
• some medications. 

How does diet affect high blood pressure?

What we eat can increase our likelihood of having high blood pressure. For example, eating above the recommended 6g of salt each day can affect your blood pressure.  Ensuring you eat a low-fat diet filled with fibre, fruit and vegetables, as well as cutting back on caffeine and alcohol, can help lower your blood pressure. 

It’s important to remember to make other healthy lifestyle changes alongside altering your diet. Regular exercise is recommended. 

How to treat high blood pressure

Lifestyle changes can help manage high blood pressure, although some people may also need medication.

Lifestyle changes

Sticking to a healthy lifestyle has many benefits, including lowering blood pressure. Try the following to maintain normal blood pressure:

Eat a balanced diet

What you eat and drink can have a big impact on your blood pressure. Understanding which foods can help to manage hypertension, reducing your salt consumption and keeping to a healthy weight are all important.

Quit smoking

Although smoking doesn't directly cause hypertension, it puts you at a greater risk of heart attack and stroke. This means if you smoke and have high blood pressure, you may be at a significantly higher risk.

Get enough exercise

Getting enough exercise helps keep your blood vessels and heart in good condition, lowering your chances of high blood pressure. On top of this, regular exercise can help you lose any excess weight – another risk factor for hypertension. Adults are recommended to get 150 minutes of exercise every week. This exercise should make you feel warm and slightly out of breath.

Reduce your stress

Feeling stressed all the time (known as chronic stress) can raise your blood pressure significantly. Try to establish what it is in your life that is causing your stress and think of ways you could look to reduce it. Understand your stress triggers and learn relaxation techniques to help you cope when they occur. Ensure you make time every day to relax – this could be five minutes of meditation, taking the dog for a walk or even enjoying a long bath.

Medication for high blood pressure

Your doctor will inform you if you need to take medication to help manage your blood pressure. Different medications may be used to help relax your blood vessels, block calcium from entering your heart and blood vessels, muscle cells, flush out excess water and salt, or make your heart beat slower and less forcefully. Medication should always be discussed with your GP before starting or stopping.

High blood pressure and weight

Being overweight can be one of several factors that increase your risk of high blood pressure. If you have been advised to lose weight, making sustainable changes to your diet and physical activity may help you manage your weight and blood pressure.

If you would like support with managing your weight, a nutrition professional can help you make changes that suit your individual needs and circumstances. You can find out more on our weight-loss page.

What is a high blood pressure diet?

A diet that is low in fat and high in fibre, fruit, and vegetables can help to lower blood pressure. Fruit and vegetables are full of vitamins and minerals our bodies need to stay fit and healthy. It is recommended that you get at least five portions of fruit and vegetables a day.

Making changes to your diet can sometimes feel challenging. A suitably qualified nutrition professional can offer personalised guidance and support, helping you find dietary changes that work for your individual needs and lifestyle.

One important aspect of reducing your blood pressure is limiting certain foods and drinks. This is because some foods can greatly increase your risk of becoming hypertensive.

Foods to lower blood pressure

It can be helpful to limit certain foods and drinks if you have high blood pressure. This can include: 

Salt

Eating too much salt can contribute to high blood pressure, so reducing your salt intake may help to lower it. Experts recommend you eat no more than 6g of salt a day. Helpful ways to do this can include:

• Avoid adding salt to meals. Instead, use herbs and spices to enhance flavour.
• Read food labels. Find out how much salt is in your food and be mindful of going over your limit.
• Limit or avoid processed foods. Most processed foods like sauces, soups and ready meals are high in salt.

Saturated fat

Eating too much saturated fat can raise cholesterol levels, which can increase your risk of heart disease and stroke. Foods high in saturated fat include fatty cuts of meat, butter, cream, cheese, cakes and biscuits.

Where possible, try replacing saturated fats with unsaturated fats, found in foods such as olive oil, avocados, oily fish, nuts and seeds.

Alcohol

Regularly drinking too much alcohol can increase your blood pressure over time. Alcohol can also interact with some blood pressure medicines. To help keep health risks from alcohol low, UK guidelines advise both men and women not to regularly drink more than 14 units a week. If you drink up to 14 units a week, it is best to spread these over three or more days.

Caffeine

Caffeine can cause a short-term increase in blood pressure. If you drink a lot of caffeinated drinks, you may want to consider reducing your intake. This could include choosing decaffeinated coffee or tea, herbal teas or water instead of some caffeinated drinks.

Foods that may help lower blood pressure

A healthy, balanced diet can play a part in managing high blood pressure. Aim to include a variety of foods, including:

• plenty of fruit and vegetables
• wholegrain foods, such as wholemeal bread, brown rice and oats
• lean sources of protein, such as fish, eggs, beans and pulses
• lower-fat dairy products.

Fruit and vegetables are also a good source of potassium, which can help support healthy blood pressure. It is best to get the potassium you need through food rather than supplements.

For personalised advice on managing your blood pressure through diet, you may wish to speak to a suitably qualified nutrition professional.

Working with a nutrition professional for high blood pressure

A nutritionist or dietitian can offer personalised guidance to help you make dietary changes that may support the management of high blood pressure. A nutrition professional may be able to help you with:

• reviewing your current diet and identifying areas where changes may be helpful
• finding practical ways to include a variety of nutritious foods in your diet
• suggesting dietary changes that take your individual needs and circumstances into account
• helping you understand how different foods and nutrients can form part of a balanced diet
• offering practical support to help you make sustainable changes.

Ready to work with a nutritionist? Enter your details in the search bar below or use our advanced search to find a qualified, experienced nutritional professional online or in person near you.

All content displayed on Nutritionist Resource is provided for general information purposes only, and should not be treated as a substitute for advice given by your GP or any other healthcare professional.