High and low blood pressure: Causes, symptoms, and treatments

How is blood pressure measured?

Blood pressure is recorded using two numbers: ”systolic” blood pressure, which is the highest pressure that’s reached within the arteries when the heart beats, and ”diastolic” blood pressure, which is the lowest pressure in the arteries, when the heart rests between beats. Both are measured in units of “mmHg”, which means  “millimetres of mercury”. These two measurements are usually written together, in the form “120/80mmHg”, which would represent a systolic pressure of 120, and a diastolic pressure of 80; and this would usually be verbally communicated as “120 over 80”. Ideal blood pressure is considered to be between 90/60mmHg and 120/80mmHg, but your doctor may give you a personalised blood pressure target that’s different, depending on your age and state of health.

How to get your blood pressure checked.

What is high blood pressure (hypertension)?

If you have a reading of 140/90mmHg or above, this is considered to be high blood pressure. However if you’re 80 or older, then it’s considered to be high if it’s over 150/90mmHg.

What are the symptoms of high blood pressure?

The symptoms of high blood pressure are rarely noticeable, which means you could be living with it without knowing. The only way to tell if you have high blood pressure is by having it measured.

When your blood pressure is high, it puts an extra strain in your heart, blood vessels, and other organs in your body. Left untreated, it can lead to potentially life-threatening conditions such as heart disease, heart failure, strokes, kidney disease, aortic aneurysms, and others.

What causes high blood pressure?

The causes of high blood pressure are not always clear, but there are several factors that increase the risk, including:

• Smoking

• Not exercising enough

• Drinking too much alcohol, coffee or other caffeine-based drinks

• Eating too much salt and too few fruits and vegetables

• Not getting enough sleep, or having poor quality sleep

• Having a relative with high blood pressure

• Aged over 65

• Being of black African or black Caribbean descent

How is high blood pressure treated?

High blood pressure can usually be successfully managed, although the recommended treatment may vary from person to person. Lowering a raised blood pressure reduces risk of developing a more serious health condition later.

By making changes to your lifestyle, it’s possible to reach and maintain a normal blood pressure. Changes you could make include:

• Stopping smoking

• Exercising regularly

• Cutting back on alcohol

• Drinking fewer caffeinated drinks

• Losing weight, if you’re overweight

There are also medicines which can be prescribed to help keep your blood pressure under control. Many people will need to take a combination of different medicines. The medicines you are prescribed may vary depending on age and ethnicity.

• If you’re under 55 years old you’ll usually be offered or an angiotensin-2 receptor blocker (ARB), or an ACE inhibitor.

• If you’re 55 years old or older or of African or Caribbean origin then you’ll usually be offered a medicine called a calcium channel blocker.

It’s important to take any medicines prescribed exactly as agreed with your doctor. When you’re taking medicine to treat high blood pressure, you will probably not feel any different – but this doesn’t mean it’s not working or that it’s not important for you to take it every day. It’s lowering your risk of worsening health in the future.

What is low blood pressure (hypotension)?

Blood pressure readings of 90/60mmHg or less are considered to be low blood pressure. This is much less common than high blood pressure.

What are the symptoms of low blood pressure?

Regularly experiencing the following symptoms could indicate low blood pressure:

• Dizziness or lightheadedness

• Feeling sick

• Blurred vision

• Generally feeling weak

• Confusion

• Fainting

If these symptoms are more noticeable when you stand up or change position, then this could be “postural hypertension”, where the body does not increase your blood pressure quickly enough when you stand up.

How is low blood pressure treated?

If your GP can identify a cause, they’ll help you to address it. This might involve looking at any medicines you’re taking, and changing them or reviewing the doses. You might be recommended to wear support stockings to improve your circulation – you can get these on prescription. Medicine is rarely needed as lifestyle changes can often bring the symptoms under control – such as drinking more water, eating smaller and more frequent meals, raising the head of your bed, and taking care when getting out of bed or standing up from a sitting position.

How to get your high blood pressure medicine from Pharmacy2U

If you’re managing high blood pressure, Pharmacy2U is here to make things easier. Our UK‑based pharmacists can deliver your medicine straight to your home, helping you avoid unnecessary trips to the GP or pharmacy. Ordering is simple, and you can do it from wherever you are. Find out more here.

Managing high or low blood pressure can feel overwhelming at times, but you’re not on your own. There are plenty of ways to stay informed and take control of your health. You can explore our range of at-home testing kits to help you understand your blood pressure levels, and our Health Hub has practical advice to support you day‑to‑day.

You can also find trusted information and guidance from organisations like Blood Pressure UK and the British Heart Foundation, who offer a wide range of helpful resources.

Further information

For more information and support about high and low blood pressure, talk to your GP or pharmacist; you may also find these links helpful.

https://www.nhs.uk/common-health-questions/lifestyle/what-is-blood-pressure/

https://www.bhf.org.uk/informationsupport/risk-factors

https://www.bhf.org.uk/informationsupport/risk-factors/high-blood-pressure