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.
Having high blood pressure (also known as hypertension) can increase your risk of developing conditions such as heart disease and stroke. High blood pressure rarely has symptoms, so it's important to have it monitored.
To help prevent hypertension, there are many lifestyle changes you can make - including diet. On this page we will explore hypertension in more detail and discuss how dietary changes can support high blood pressure management.
Understanding blood pressure
To find out your blood pressure you will need two measurements to be taken within a single heartbeat. One is the systolic pressure - the level of pressure when your heart is pumping blood. The other is diastolic pressure - the level of pressure when your heart is resting before it pumps again.
The measurement for blood pressure is in millimetres of mercury (mmHg) and the readings are given in the form of two numbers. The first number is your systolic reading and the second number is your diastolic pressure. So, if your systolic reading is 120mmHg and your diastolic reading is 80mmHg, your blood pressure would be 120 over 80. Doctors typically write this as 120/80.
To measure your blood pressure a manual or automatic device can be used. Your doctor will place a cuff around the top of your arm and pump it full of air to temporarily restrict blood flow. The air is then slowly released while your pulse is checked. Hearing the way your pulse beats once the air has been released allows a measurement to be taken.
For an accurate reading, you should be seated with your legs uncrossed and your back supported.
If your reading is continually higher than average, you may be diagnosed with hypertension. It is estimated that around 30% of people in England have high blood pressure, but many don't realise they have it.
Symptoms of high blood pressure
High blood pressure is often referred to as the 'silent killer', this is because it rarely has any noticeable symptoms. If high blood pressure is left untreated it can lead to serious health conditions including kidney failure, stroke and heart attack.
In extreme cases and when blood pressure is very high, there can be noticeable symptoms, including:
- blurred/double vision
- constant headaches
- shortness of breath.
If you are experiencing any of these symptoms, you should see your doctor as soon as possible.
As there are rarely symptoms you can see or feel, it is recommended that you have your blood pressure monitored regularly - adults are advised to get it checked at least once every five years.
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.
Who is at risk?
The risk of having high blood pressure increases as you get older, especially after the age of 65. As well as age, there are other risk factors - these include:
- being overweight
- not taking enough exercise
- not eating a balanced diet
- drinking too much alcohol
- being a smoker
- having a family history of high blood pressure.
If you fall into these categories, making changes to your lifestyle and diet can help you manage your blood pressure. You should also have your blood pressure checked more regularly, ideally once a year.
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 pregnancy-induced hypertension, which can lead to a condition called pre-eclampsia. This can compromise the placenta - the organ that links the mother's and baby's blood supply.
Taking gentle exercise and eating a diet with foods to lower blood pressure can help reduce your risk.
In most cases (90% in fact) the 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 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:
- hormonal conditions
- tissue-related conditions (like lupus)
- kidney disease
- narrowing of arteries supplying the kidneys
- oral contraceptive pill
- certain painkillers
- recreational drugs (like cocaine and crystal methamphetamine).
Many people find a change in diet and lifestyle alone can treat high blood pressure, although you may be recommended medication too. Your doctor will advise as to whether or not you need medication, but making lifestyle changes are recommended either way.
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. We will go into this in more detail further down the page.
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 will be at a significantly higher risk.
Get enough exercise
Taking enough exercise will help to 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.
As aforementioned, your doctor will inform you if you need to take medication to help manage your blood pressure. There are several different medications for hypertension, including:
- ACE inhibitors - These work by relaxing the blood vessels.
- Calcium channel blockers - These block calcium from entering the muscle cells of the blood vessels and heart, widening the vessels and lowering blood pressure.
- Diuretics - These flush out excess water and salt from the body.
- Beta-blockers - These make your heart beat slower and less forcefully.
High blood pressure and weight
If you are overweight, your heart has to work harder to pump blood around the body and this can raise blood pressure. If you do need to lose weight, it's useful to remember that losing even a few pounds will make a difference.
The best way to lose excess weight is to follow a balanced, calorie-controlled diet and increase your physical activity. Many find it helpful to get professional support from a nutritionist to help them lose weight - you can find out more on our weight-loss page.
High blood pressure diet
A diet that is low in fat and high in fibre and 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.
Changing your eating habits can be difficult - even when we know the health benefits. This is why many people seek support from a suitably qualified nutrition professional. These professionals will not only create a diet plan for you to follow, they will also provide support to help you change your habits.
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 limit
The following foods should be limited when addressing high blood pressure:
Salt is known to affect blood pressure - the more salt you consume, the more likely it is that your blood pressure will rise. Salt has such a significant impact, that many people find cutting their intake is all that's needed to lower their blood pressure.
Experts recommend you eat no more than 6g of salt a day, which is around a teaspoon. Take a look below for some tips to reduce your salt intake:
- Don't add salt to your meals. Use herbs and spices to enhance flavour instead.
- Read food labels. Find out how much salt is in your food and be mindful of going over your limit.
- Avoid processed foods. In most cases, salt is added during processing, so processed foods like sauces, soups and ready meals are typically high in salt.
Having too much cholesterol in your blood can increase your risk of heart disease and stroke. If you have high blood pressure, it is very important to keep cholesterol levels low. Saturated fats raise your cholesterol, so be sure to limit these in your diet.
Saturated fats (also known as the 'bad' fats) are typically found in fatty cuts of meat, cream, cheeses, cakes, and biscuits. Reducing your intake of these and swapping them for healthier alternatives will help to lower cholesterol and improve your general health.
In contrast to this, monounsaturated and polyunsaturated fats actually help to lower cholesterol. These types of fats can be found in olive oil, avocados, vegetable oils, oily fish and nuts and seeds. Include these in your diet, but remember as they are still technically fats, they can cause weight gain if you overindulge. Enjoy in moderation.
If you regularly drink more than the recommended amount of alcohol, over time your blood pressure will rise. On top of this, alcohol can affect blood pressure medication, making it less effective. Staying within the recommended limits is the best way to help manage your blood pressure. Current guidelines recommend that both men and women should drink no more than 14 units of alcohol per week - this equates to no more than one to two units a day.
Alcohol is also high in calories, which can contribute to weight gain. Gaining too much weight can lead to high blood pressure, so it is important to stay a healthy weight.
It is thought that drinking more than four cups of coffee a day can increase blood pressure. While more research is required to understand the effects caffeine has on blood pressure, you may benefit from limiting the amount you consume.
Try the following:
- herbal teas instead of coffee
- flavoured sparkling water instead of caffeinated soft drinks
- naturally energy boosting foods instead of energy drinks.
Foods to lower blood pressure
Research suggests that as well as reducing the food groups described above, you should look to include foods that contain the following key minerals:
- Calcium - This helps blood vessels tighten and relax when they need to.
- Magnesium - This helps to regulate many body systems, including blood pressure.
- Potassium - This is important for muscle function and helps to relax the walls of blood vessels.
These three minerals, in particular, are believed to help reduce hypertension. Try to include the following foods to lower blood pressure:
- Spinach - high in fibre and a good source of potassium and magnesium.
- Sunflower seeds - these make a great snack and contain magnesium (enjoy unsalted varieties).
- Beans - great for overall heart health, beans are full of fibre and contain potassium and magnesium.
- Banana - an ideal on-the-go snack, bananas are a good source of potassium.
For more advice on foods to lower blood pressure, you are advised to seek a nutrition professional.
Content has been reviewed by a dietitian. 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.