Orthostatic hypotension

24th August 2023 | Dr Melanie Dani

Introduction

Orthostatic hypotension describes a lowering of blood pressure that occurs on standing up. The strict criteria are a fall of more than 20 mmHg systolic blood pressure, and/or more than 10 mmHg fall in diastolic blood pressure after standing for 3 minutes.

This condition is particularly common in older people, as well as those suffering from high blood pressure (hypertension), which is often the opposite of what one may expect. It is a common cause of falls, fainting, injury, and an unpleasant ‘headrush’ on standing. It is particularly common in people who have been unwell for a period of time and have been confined to bed or inactivity. Overall, it is a sign that your autonomic nervous system and blood pressure reflexes are not working as well as they should be.

What Triggers it

One of the commonest culprits in causing orthostatic hypotension is medications. These include blood pressure medications, heart rate medications and diuretics (‘water’ tablets) but also antidepressants, other mental health drugs, and painkillers.

It is not unusual to have high blood pressure when resting and then orthostatic hypotension on standing up. This can be a very difficult to manage, because it is important to treat both high blood pressure (which can cause harm and long term cardiac risks) and low blood pressure (which is not dangerous in itself, but can be dangerous if it causes you to fall) at the same time. Often, we need to consider a careful balance of safety, quality of life, and what is acceptable for each individual person It can take time to find a balance of interventions that suit a particular patient, and this balance can change over time.

How Do I Handle It?

Here are some simple tips if you think you may be suffering from orthostatic hypotension:

1. check your blood pressure in both a supine (lying flat) and standing position after 1 and 3 minutes. A drop of more than 20 mmHg systolic and 10 mmHg diastolic after 3 minutes suggests orthostatic hypotension.

2. consider your medications. Many medications can cause this problem, and it is worth discussing this with your doctor and considering the benefits of the intended medication alongside the disadvantages when deciding whether to stop it or not

3. a common cause of orthostatic hypotension is dehydration or low blood volume. Therefore we generally advise people to make sure they drink enough is usually 2 to 3 L/day (if they have not been advised that you need a fluid restriction). A large glass of water before standing up can be helpful, especially in the morning or if you have been resting for a long time. 

4. if you have a low resting blood pressure then adding salt to your diet is useful, but if you have a resting high blood pressure then this is not advised 

5. compression garments and abdominal binders are very important in this situation. You should avoid lying in the flat position and at night try to sleep with the head of your bed raised to 10 or ideally 30 degrees 

6. eat small and frequent meals, and moderate your carbohydrate intake, which will can regulate your blood pressure 

7. have a night-time carbohydrate snack such as cereal or toast and jam to help lower your night-time blood pressure values and avoid dehydration in the morning 

8. one of the most important things is being aware of your symptoms and knowing to get up slowly. Clenching the muscles in your legs buttocks and belly will help return blood to your heart and avoid your symptoms.

What I have a high resting blood pressure and suffer with dizziness from low BP?

This is a particularly challenging combination of symptoms to treat. Risk factors for this particular combination of high and low BP states include longstanding diabetes, and/or hypertension, but we can also see patients without these risk factors develop symptoms in later life. 

The autonomic nervous system which normally controls the BP and heart rate can fail to regulate these adequately, and as consequence both extremes of BP are seen. 

It may also be the case that some patients may have had a longstanding history of high BP, with multiple medications, and over time, the multiple medications may be too “strong” for BP control and lead to lower BP states at times, leading of loss of consciousness. 

The advice above under “How do I handle it” is helpful and the following article may be helpful for your doctor  / GP. 

You may wish also to print this and read up on the top tips and tricks to help navigate your symptoms. 

Conclusion

It is important to keep liaising with your doctor until your symptoms are under control. Sometimes it is not possible to completely ‘cure’ this problem, but learning to modify your activity and lifestyle you can get it under control. The balance can change over time, as well as your need for particular medications for both low and high blood pressure.

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