Low blood pressure Q&As
Published by Bupa's health information team, March 2009.
Answers to questions about low blood pressure
This section contains answers to common questions about this topic. Questions have been suggested by health professionals, website feedback and requests via email.
- What happens in a tilt test?
- Why can diabetes cause postural hypotension?
- Why is low blood pressure beneficial?
What happens in a tilt test?
In a tilt test, you lie on a table, where you are secured with safety belts, and are slowly tilted upwards. This is so your blood pressure and heart rate can be monitored while you are in an upright position.
Explanation
A tilt test is normally done as an outpatient appointment, which means you will need to go to hospital, but will not have to stay overnight.
When you go for the test, you will be asked to lie down on the tilt table and safety belts will be placed around your body, to help keep you secure. Small sticky patches, called electrodes, will be attached to your chest so that your heart rate and rhythm can be monitored, and a small cuff placed around your arm or finger, to monitor your blood pressure.
Your blood pressure and heart rhythm will be recorded while you are lying down on the table. The table will then be tilted up until you are almost in an upright position. You will remain in this position for up to an hour while your blood pressure and heart rhythm continue to be monitored. The test will be stopped earlier if you have a drop in your blood pressure or heart rate. At the end of the test, you will be lowered back down to a lying position.
You may start to get symptoms during the test, such as feeling light-headed, feeling sick and sweating. Some people who have the test faint. If this happens, it normally only lasts for a short time and the bed will be lowered while you recover.
The results of your test will be reported to your doctor and he or she will discuss them with you at your next appointment.
Further information
- Arrhythmia Alliance
01789 450787
www.heartrhythmcharity.org.uk
Sources
- Tilt test. Arrhythmia Alliance. www.heartrhythmcharity.org.uk, accessed 21 February 2008
Why can diabetes cause postural hypotension?
Diabetes can cause damage to your nerves, which carry signals from your brain to your muscles, skin, blood vessels and other organs. This is called neuropathy. When this affects the nerves controlling blood vessels in your legs, it can cause postural hypotension (a drop in blood pressure when you stand up).
Explanation
Normally when we stand up, the veins in our legs automatically constrict (become narrower), preventing blood from pooling in the legs. In postural hypotension, the nerves controlling these veins don't work as they should, so when you stand up, the veins don't constrict. This means that the blood remains in your legs, leading to a lack of blood reaching your brain, and symptoms such as fainting and dizziness.
Diabetes is one of the reasons why these nerves can become damaged and stop working properly. The exact reasons why diabetes can cause damage to the nerves is not fully understood at present. However, it is known that the high levels of glucose (sugar) in the blood that occurs in diabetes can cause chemical changes in the nerves. This damages their ability to transmit signals.
For this reason, it is important that your diabetes is properly controlled.
Further information
- Diabetes UK
0207 424 1000
www.diabetes.org.uk
Sources
- Low blood pressure. Blood Pressure Association. www.bpassoc.org.uk, accessed 18 February 2008
- Kumar P, Clark M. Clinical Medicine. 6th ed: Elsevier, 2005
Why is low blood pressure beneficial?
Having a low blood pressure means you are less likely to get diseases involving the circulation, such as stroke and coronary heart disease.
Explanation
If your blood pressure is high, it can cause a strain on the arteries that carry blood around your body. This can cause the arteries to become weakened and clogged up, restricting blood flow to the various organs around your body. This may lead to stroke, kidney failure, eye conditions and diseases of the heart.
The lower your blood pressure, the less likely you are to suffer from these problems. There are a number of factors that normally increase your risk of getting high blood pressure, such as having too much salt in your diet. However, people with a naturally low blood pressure seem to be protected from these factors to some degree.
Further information
- Blood Pressure Association
020 8772 4994
www.bpassoc.org.uk
Sources
- Low blood pressure. Blood Pressure Association. www.bpassoc.org.uk, accessed 18 February 2008
Related topics
This information was published by Bupa's health information team and is based on reputable sources of medical evidence. It has been peer reviewed by Bupa doctors. The content is intended for general information only and does not replace the need for personal advice from a qualified health professional.
Publication date: March 2009
Low blood pressure factsheet
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