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postural hypotension Alternative Names
orthostatic hypotension
Definition
Postural hypotension is low blood pressure that occurs when a person stands up. It results in decreased blood flow to the brain.
What is going on in the body?
When a person goes from sitting or lying to a standing position, gravity can cause blood to pool in the lower half of the body. This can lower the blood pressure. However, the body has many ways to prevent this from happening, such as the heart pumping harder. In various conditions, the body is unable to prevent abnormally low blood pressure from happening when a person stands up. This can lead to symptoms and is called postural hypotension.
What are the signs and symptoms of the infection?
Symptoms of postural hypotension occur when a person stands up. They may include: What are the causes and risks of the infection?
Postural hypotension has many possible causes, including: - dehydration, often from excessive vomiting, or severe diarrhoea
- decreased blood volume, which can occur with excessive bleeding
- drugs or medications, such as alcohol, the blood pressure medication prazosin, or the diuretic called frusemide
- prolonged bed rest
- old age, which can decrease the body's natural ability to maintain the blood pressure when a person stands up
- damage to the nervous system, such as that from diabetes, Parkinson's disease, and spinal cord injury
- heart conditions, such as a heart attack, congestive heart failure, or a problem with a valve in the heart called aortic stenosis
- anaemia, or a low red blood cell count
- blood vessel problems, such as severe varicose veins
- low adrenal hormone levels, also called adrenal insufficiency
Other causes are also possible. Sometimes, no cause can be found.
What can be done to prevent the infection?
Prevention of postural hypotension is related to the cause. Making sure to get enough fluids can help prevent cases due to dehydration. Avoiding certain drugs can prevent cases from this cause. Avoiding prolonged bed rest can help prevent this cause. Many cases cannot be prevented.
How is the infection diagnosed?
The doctor often suspects this condition after the history and physical examination. The blood pressure can be measured when a person is lying down, sitting, and standing. If the blood pressure drops abnormally when a person stands up, the diagnosis can be made.
Other tests may be needed to determine the cause. For example, a blood test called a cortisol level can help detect low adrenal hormone levels. A blood test called a blood glucose level can help diagnose diabetes. An imaging test of the heart called echocardiography can help diagnose heart failure or aortic stenosis. Other tests may also be used, depending on the suspected cause.
What are the long-term effects of the infection?
If someone with postural hypotension faints when he or she stands up, there is a potential for injury. Most long-term effects are related to the cause. For example, a spinal cord injury can leave someone with permanent numbness or paralysis. Cases due to dehydration or drugs are usually treatable and often have no long-term effects.
What are the risks to others?
Postural hypotension is not contagious, and poses no risk to others.
What are the treatments for the infection?
Treatment is usually directed at the cause of the postural hypotension. If dehydration is the cause, fluids can be given. If a medication is the cause, the medication can be stopped or the dose lowered. If a heart condition is the cause, a person may need medication or surgery to treat it.
In cases that cannot be treated directly, such as nervous system damage or old age, medication may be used to keep the blood pressure up. Salt tablets, support stockings for the legs, medication called corticosteroids, and other treatments may be used.
It is important for a person with postural hypotension to get up slowly and have something or someone to hold onto when standing. If symptoms occur, the person should sit back down.
What are the side effects of the treatments?
Side effects depend on the treatment used for the postural hypotension. For example, corticosteroids may cause osteoporosis, mood swings, and high blood sugar levels. Surgery carries a risk of bleeding, infection, and allergic reaction to anaesthesia.
What happens after treatment for the infection?
The success of treatment and the need for follow-up depend on the cause of the postural hypotension. For example, those who developed this condition due to a medication often need no further treatment or monitoring when the medication is stopped. Those with nervous system damage or heart disease may need lifelong monitoring and treatment.
How is the infection monitored?
Repeated measurements of the blood pressure while lying down, sitting, and standing are often used for monitoring. Any medications used may need monitoring, which can include blood tests. The underlying cause may also need monitoring. For example, those with diabetes need to check their blood sugar levels regularly. Any new or worsening symptoms should be reported to the doctor.
Author: Adam Brochert, MD
Reviewer: HealthAnswers Australia Medical Review Panel
Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia
Last Updated: 1/10/2001
Contributors
Potential conflict of interest information for reviewers available on request |
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