Patient information from BMJ

Postural hypotension (low blood pressure when you stand up)

Last published:Nov 18, 2022

​Postural hypotension is the name for the sudden drop in blood pressure that happens to some people when they stand up after lying down. It can make you feel light headed, which can lead to falls and injuries.

This type of low blood pressure happens a lot as we get older. But there are things you can do to help prevent it. You can use our information to talk with your doctor about the best treatments for you.

What is postural hypotension?

Most people know that high blood pressure (called hypertension) can lead to serious medical problems, such as heart attacks and strokes. But low blood pressure (called hypotension) can also cause problems.

Postural hypotension (you may also hear it called orthostatic hypotension) is a sudden drop in blood pressure that happens when you stand up. It can cause light-headedness and dizziness, which can lead to falls and injuries, especially in older people.

What happens?

Whenever you stand up, your blood naturally flows downwards in your body, towards your legs and feet and away from your heart and brain.

To stop this happening too much, your blood vessels instantly get a bit narrower (they constrict) when you stand up. This stops your blood from pooling in your legs too quickly, and helps keep it flowing steadily around your body.

But if your blood vessels don’t constrict properly your heart can struggle to pump enough blood to your brain. This causes the symptoms, such as dizziness, that can lead to falls.

Why does it happen?

The most common cause of postural hypotension is getting older. Our blood vessels, and the nerves and muscles that control them, don’t work as well as we age. Postural hypotension affects more than 20 in every 100 people over the age of 80.

Several other things can cause postural hypotension. They include:

• Some medicines

• Conditions that can affect the nerves in the hands and feet, such as diabetes

• Deing dehydrated

• Parkinson’s, and

• A type of dementia called Lewy body dementia.

What are the symptoms?

The symptoms of postural hypotension happen when you stand up from a lying-down position, and they should get better when you sit or lie down again. They include:

• Feeling light headed

• Dizziness

• Weakness

• Feeling faint

• Feeling tired when you exert yourself, and

• Changes in your vision: for example, you may have dimmed vision, tunnel vision, or be unable to see anything for a short time.

Many people’s symptoms are worse at certain times or places, such as:

• Early in the morning, when people tend to be a little dehydrated

• In hot weather or in hot buildings

• After meals

• After standing still for a while, and

• During or after exercise, when blood vessels widen.

If you see your doctor with symptoms that suggest postural hypotension, they will test your blood pressure when you are sitting and standing, to measure the difference.

They may also ask you to take your own blood pressure at home for a day or so. They will show you how to do this and how to record the measurements.

What treatments are available?

Treatments for postural hypotension aim to:

• Prevent or relieve your symptoms

• Improve your quality of life, and

• Prevent falls and injuries.

The first things your doctor may suggest are some changes to your lifestyle and routines that may help with your symptoms. For example, they may suggest that you:

• Take care, when you stand up after lying down, go into a sitting position for a few moments first

• Try not to strain too much when sitting on the toilet. If you have problems with constipation, there are medicines that can help

• Eat small, frequent meals. This helps prevent your blood pressure from falling too much after eating

• Take care when blowing hard through your mouth - for example, if you blow up a balloon or play a woodwind or brass musical instrument

• Use a bedside commode (pot) if you need to get up to urinate during the night

• Do small, gentle exercises when standing, such as crossing your legs, standing on your tiptoes, and tensing your leg muscles. These all help to push blood back to your heart, and to keep it fit

• Stay well hydrated - drink plenty of non-alcoholic fluids

• Try to avoid lying down during the day. If you need to lie down, get up slowly afterwards, and sit for a while before standing

• Be aware of standing for a long time in hot environments, and

• Use blocks to raise the head of your bed by 15 to 22cm (6 to 9 inches). This helps your body to retain salt and water, which stops your blood pressure from falling too much in the morning.

Your doctor may also advise you to add more salt to your diet, to help keep your blood pressure a little higher and to prevent dehydration. But you shouldn’t do this yourself without talking to your doctor first and having your blood pressure taken properly.

Some people wear custom-made, full-length elastic stockings to help prevent too much blood from pooling in their legs, although some people find these awkward to use. Your doctor can tell you more about these.

Medicines

Drug treatments for postural hypotension may mean taking medicines to stop your blood pressure dropping too much. You usually take these at night.

But your doctor will want to get the right balance between not letting your blood pressure get too low or too high. So, if you take these drugs your doctor will want to check on you every few months.

Some medicines can actually cause low blood pressure. So your doctor may advise you to try to reduce the dose of these, or stop taking them completely. You can talk with your doctor about what may work best for you.

Medicines that can cause low blood pressure include:

• Drugs used to relax muscles (including those that help men who have an enlarged prostate)

• Diuretics, which stop the body from retaining too much water, and

• Some drugs used to treat anxiety and depression.

If you decide to stop taking drugs that help with prostate problems, this can make you more likely to get urinary tract or bladder infections. So your doctor should talk to you about the symptoms to look out for, and what to do if it happens.

What to expect in the future

Postural hypertension is often the result of another condition, such as diabetes. So the outlook largely depends on how that other condition is affecting you.

For example, if your diabetes treatment goes well, then your problems with blood pressure should not get worse over time.

The things that cause postural hypotension can’t always be reversed or cured. But many people find that making changes to their lifestyle or trying different treatments can help them to manage their symptoms.