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Low blood pressure (hypotension)


Expert reviewer, Dr Tim Cripps, Consultant Cardiologist
Next review due August 2021

Low blood pressure is when your blood pressure falls much lower than is normal for you. You may be a person who has naturally low blood pressure which isn’t causing any problems. But if your blood pressure becomes lower than usual for you, it can cause symptoms such as dizziness and fainting.

The medical name for low blood pressure is hypotension. Low blood pressure can happen for a variety of reasons such as medication you’re taking or an underlying health condition you have.

What is blood pressure?

Your blood pressure is a measure of the force that your blood puts on the walls of your arteries as it's pumped around your body. Your blood pressure changes throughout the day. It’s lower when you sleep, and it rises when you wake up.

You’ll see blood pressure shown as two numbers such as 120/80mmHg. The first number is the peak pressure when your heart contracts – your systolic blood pressure. The second number is the pressure when your heart is fully relaxed – your diastolic blood pressure. The letters mmHg mean millimetres of mercury, the units used to measure blood pressure.

There’s no recognised cut-off level for low blood pressure that applies to everyone. For instance, a systolic pressure of 90 may be too low for some people, but normal for many young, healthy adults. Low blood pressure is usually only considered to be a problem if you’re having symptoms.

If your blood pressure is too high (hypertension), you may be at greater risk of certain diseases such as coronary heart disease and stroke. A blood pressure of 140/90mmHg or more is considered to be high.

Types and causes of low blood pressure

The main types of hypotension are as follows.

  • Postural (orthostatic) hypotension – low blood pressure when you stand up. If you have postural hypotension, your body doesn't respond quickly enough when you stand up. Blood stays in your legs, causing your blood pressure to fall. Postural hypotension is common, especially in older people. It’s more likely to happen if you’re taking certain medicines, are dehydrated, have spent a long time in bed or you’ve had a hot bath. It can also happen after eating a meal, especially one high in carbohydrates. This is known as postprandial hypotension.
  • Neurally mediated hypotension. This is also called reflex syncope (fainting). This is an occasional sudden but temporary drop in blood pressure which can make you lose consciousness briefly. This may happen if you’ve been standing for a long time. It can also be triggered by pain, emotional stress or fear (for example, if you have a phobia). Neurally mediated hypotension affects children and young people more than other age groups.
  • Severe hypotension (shock). This is a life-threatening condition where your blood pressure drops very low and your vital organs don’t get the blood they need. It can happen in a number of serious medical conditions. These include severe infections, heart attack, severe allergic reactions or major blood loss. If you have severe hypotension, you need immediate medical attention.

There may be an underlying medical condition that’s causing your low blood pressure. Examples include heart disease, Parkinson’s disease and diabetes. You may also get low blood pressure during pregnancy. See our FAQs below for more about low blood pressure and diabetes, and low blood pressure in pregnancy.

Your GP will be able to tell you more about the type of low blood pressure you have, and what might be causing it.

Symptoms of low blood pressure

If your blood pressure is naturally low, you’re unlikely to have any symptoms and it's not something you should be concerned about. 

However, if your blood pressure becomes lower than usual for you, it can cause symptoms such as:

  • dizziness or light-headedness
  • fainting
  • palpitations (you can feel your heart beating more forcefully)
  • feeling sick
  • blurred vision
  • feeling confused or unable to concentrate 

If you keep having symptoms like these, contact your GP.

Diagnosis of low blood pressure

Your GP will ask about your symptoms and examine you. They’ll measure your blood pressure using either an automated digital device or a manual device. To find out more, see our video Having your blood pressure taken in the introduction above.

If you have symptoms of postural hypotension (low blood pressure when you stand up), your GP may also measure the change in your blood pressure while you’re sitting (or lying) and then standing. If it’s much lower when you stand up compared with when you’re sitting down, this suggests you have postural hypotension.

Your GP may also recommend that you have some blood tests to check your general health. If they think that your low blood pressure may be linked to an underlying problem with your heart, they may offer you further tests. These may include an electrocardiogram (ECG) and an echocardiogram (ultrasound of your heart).

If your GP refers you to a hospital specialist, they may recommend a test called a tilt test to understand what’s causing your symptoms. The test involves being slowly tilted from lying down to an upright position on a table as your blood pressure, heart rate and rhythm are monitored. For more information, see our FAQ: What happens in a tilt test? below.

Self-help for low blood pressure

There are some simple steps you can take to help limit the symptoms of common types of low blood pressure.

If you have postural hypotension and get symptoms when you sit up or stand, your GP may suggest some of the actions described below.

  • Stand up slowly from sitting or lying down, especially when you first wake up.
  • If you have to spend a long time in bed, try to sit up each day and even do some exercises in bed.
  • Take care getting out of hot baths or showers. It may be best to avoid very hot baths.
  • Make sure you drink plenty of fluid so you don’t get dehydrated.
  • If you drink alcohol, stick to the recommended daily limits.
  • Raise the head of your bed a little. 

If you have postprandial hypotension and get symptoms after eating a meal, the following may help.

  • Eat smaller meals more frequently, with less carbohydrate (that is, less sugar and starchy food such as rice, bread and pasta).
  • Lie down, or at least avoid sudden standing after a meal.

If you know you may faint in certain situations, it’s a good idea to try and avoid these. This might include not standing still for long periods.

Remember – if you feel faint, you should immediately sit or lie down if you can do so safely. Put your feet up so that they are higher than the level of your heart. If you can’t sit or lie down, then at least squat down. If your symptoms don’t go away, seek medical attention.

Treatment for low blood pressure

You’re unlikely to need any treatment if your blood pressure is naturally low and you don't have any symptoms. If you have symptoms, there are usually simple things you can do to help yourself. See our section on self-help above for more information.

If you have postural hypotension (low blood pressure when you stand up), your GP may suggest that you have more salt in your diet. However, don't increase the amount of salt you have unless your doctor suggests it because this may affect other health conditions you have.

If you’re able to do them, you may be shown some special movements such as leg crossing and squatting. These may help to avoid hypotension happening while you stand. Your GP may also suggest you wear compression stockings. These can help stop blood staying in your legs.

Medicines

Sometimes, low blood pressure can be caused by the medicines you’re taking. Your GP may review your medicines to see if there are any that could be making your symptoms worse or bringing them on. They may suggest stopping or changing your medication to see if that helps. It’s important that you don’t stop or change any of your medicines without discussing it with your GP first.

Your GP or a specialist may prescribe medicines if self-help measures don’t stop your symptoms of low blood pressure. These may include medicines that:

  • increase how much salt is in your body
  • make your veins constrict

You may need treatment for any underlying health condition that’s causing your low blood pressure. If so, your GP will discuss with you what’s best in your particular circumstances.

Frequently asked questions

  • A tilt test can help to find out what may be causing symptoms such as fainting and dizziness. The test is usually done as an outpatient appointment. This means you’ll go to hospital to have the test but you won't need to stay overnight.

    When you go for the test, you’ll be asked to lie down on the tilt table, which has a footrest at the end. Safety belts will be placed around your body to keep you secure. Wires, called electrodes, will be attached with sticky patches to your chest so that your heart rate and rhythm can be monitored. A small cuff will be placed around your arm to monitor your blood pressure.

    Your blood pressure and heart rhythm are recorded while you’re lying down on the table. The table will then be gradually tilted until you’re almost upright. You’ll probably stay like this for up to 45 minutes while your blood pressure and heart rhythm are monitored. You may also be given a medicine to help improve the accuracy of the test.

    At the end of the test, you’ll be lowered back down into a lying position.

    You may start to get symptoms during the test, such as sweating or feeling light-headed or sick. It’s also possible that you may faint during the test. If this happens, the bed will be returned to a flat position to allow you to recover.

    The results of your test will be reported to your doctor so they can discuss them with you at your next appointment.

  • When you stand up, your body has to make some changes to stop your blood staying in the lower half of your body. These are quite normal and include an increase in your heart rate and constriction (narrowing) of the blood vessels in your legs.

    Both type 1 and type 2 diabetes can damage your nerves. This is called diabetic neuropathy. Diabetic neuropathy can affect the nerves to your blood vessels, so preventing them from getting the message to constrict when you stand up. This means that blood pools (stays) in your legs, reducing the amount that reaches your brain and causing symptoms such as fainting and dizziness. This is postural hypotension.

  • It may be. Having blood pressure which is too high is a risk to your health. High blood pressure can lead to serious conditions such as stroke, coronary heart disease and kidney failure. The lower your blood pressure, the less likely you are to suffer from these problems.

    However, if your blood pressure becomes too low, which means lower than is normal for you, it can cause problems. You may become unsteady and even faint.

    There are a lot of things you can do to help keep your blood pressure in a healthy range. These include:


    It’s best to have your blood pressure checked regularly (at least every five years). Follow any advice your GP or practice nurse gives you about how to keep it at a healthy level.

  • Your midwife will check your blood pressure at each antenatal appointment. This is just part of making sure you and your baby are healthy.

    It’s normal for your blood pressure to become lower during pregnancy. This is mainly because your hormones relax the walls of your blood vessels. Your blood pressure may fall very early in your pregnancy and reach its lowest point during your second trimester (weeks 13 to 28). It then starts to rise again, returning to normal after you have your baby.

    If you have low blood pressure during pregnancy, you may feel faint and dizzy suddenly when you get up from lying or sitting. This is called postural hypotension. See our section on types and causes of low blood pressure above for more information.

    You can help relieve your symptoms of postural hypotension by making sure you get up slowly from lying or sitting. If you feel you’re going to faint, it’s important to sit or lie down right away. See our section on self-help above for more tips on coping with low blood pressure.

    Towards the end of your pregnancy when your baby is quite large, you may feel faint when lying on your back. This is because, in this position, your baby is pressing on the main vein returning blood to your heart. You can help prevent this by lying on your side.

    Doctors aren’t sure yet whether having a low blood pressure during pregnancy can cause your baby any harm. Different studies have shown different results so more research is needed to be certain.

    Occasionally, symptoms of low blood pressure are caused by other underlying health conditions affecting your pregnancy. Always tell your midwife about your symptoms. Seek medical help if you have dizziness or fainting or any other symptom that you’re worried about.


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Related information

    • Assessment of hypotension. BMJ Best practice. bestpractice.bmj.com, last updated June 2018
    • Orthostatic hypotension. BMJ Best practice. bestpractice.bmj.com, last updated November 2017
    • Hypotension. PatientPlus. patient.info/patientplus, last checked December 2016
    • Hypertension. PatientPlus. patient.info/patientplus, last checked December 2016
    • Hypertension treatment. PatientPlus. patient.info/patientplus, last checked December 2016
    • Physiological changes in pregnancy. PatientPlus. patient.info/patientplus, last checked June 2016
    • Antepartum haemorrhage. PatientPlus. patient.info/patientplus, last checked March 2016
    • Orthostatic hypotension. The MSD Manuals. www.msdmanuals.com, last full review/revision June 2018
    • Tilt table testing. The MSD Manuals. www.msdmanuals.com, published September 2017
    • Antenatal care for uncomplicated pregnancies. National Institute for Health and Care Excellence (NICE), March 2008 (updated January 2017). www.nice.org.uk
    • Hypotension. National Heart, Lung, and Blood Institute. www.nhlbi.nih.gov, accessed August 2018
    • Alagiakrishnan K. Postural and postprandial hypotension: approach to management. Geriatr Aging 2007; 10(5):298–304
    • The Task Force for the Diagnosis and Management of Syncope of the European Society of Cardiology (ESC), et al. 2018 ESC Guidelines for the diagnosis and management of syncope. Eur Heart J 2018; 39(21):1883–1948. doi:10.1093/eurheartj/ehy037
    • Tilt table test. Syncope Trust And Reflex anoxic Seizures (STARS), 2017. www.stars.org.uk
    • Diabetic neuropathy. Medscape. emedicine.medscape.com, published March 2018
    • 2013 ESH/ESC Guidelines for the management of arterial hypertension: The Task Force for the management of arterial hypertension of the European Society of Hypertension (ESH) and of the European Society of Cardiology (ESC). Eur Heart J 2013; 34(28): 2159–219. doi:10.1093/eurheartj/eht151
    • Sanghavi M, Rutherford J. Cardiovascular management in pregnancy. Circulation 2014; 130:1003–08. doi:10.1161/CIRCULATIONAHA.114.009029
    • Chen A, Basso O. Does low maternal blood pressure during pregnancy increase the risk of perinatal death? Epidemiology 2007; 18(5):619–22
    • Warland J. Low blood pressure. BMC Pregnancy Childbirth 2012; 12(S1):A9
    • Warland J, McCutcheon H and Baghurst P. Maternal blood pressure in pregnancy and stillbirth: a case-control study of third-trimester stillbirth. Am J Perinatol 2008; 25:311–17. doi:10.1055/s-2008-1075031
    • Personal communication Dr Tim Cripps, Consultant Cardiologist, August 2018
  • Reviewed by Dr Kristina Routh, Freelance Health Editor, Bupa Health Content Team, August 2018
    Expert reviewer, Dr Tim Cripps, Consultant Cardiologist
    New review due August 2021



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