Definition
A subarachnoid hemorrhage (SAH) is bleeding in the space that surrounds the brain. This can raise pressure around the brain. SAH can be deadly.
Causes
SAH may be caused by:
- Head trauma
- Broken cerebral aneurysms and other unusual blood vessel problems
Risk Factors
SAH is more common in people who are aged 50 years and older. Other things that may raise the risk are:
- Having family members who have had aneurysms
- Having certain genetic syndromes, such as Ehlers-Danlos syndrome
- High blood pressure
- Smoking
- Alcohol use disorder
- Substance use disorder
- Use of combined oral contraceptives (in women)
Symptoms
Problems may be:
- Sudden, severe headache
- Nausea and vomiting
- Stiff neck
- Light sensitivity
- Loss of consciousness
- Seizures
Diagnosis
The doctor will ask about your symptoms and health history. A physical exam will be done. This may be enough to suspect the diagnosis.
Pictures may be taken of the brain and the structures around it. This can be done with:
The fluid in the spine may need to be tested. This can be done with a lumbar puncture.
CT Scan of the Head |
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Treatment
Emergency care is needed right away. The goals of treatment are to:
- Stop the bleeding
- Limit harm to the brain
- Reduce the risk of another SAH
Options are:
- Surgery to stop an aneurysm from bleeding
- Medicines to help blood flow to the brain, to ease pain, and to treat other symptoms, such as seizures
Rehabilitation will be needed when a person is stable. This may include speech, physical, and occupational therapy.
Prevention
SAH cannot always be prevented. To lower the risk:
- Manage high blood pressure
- Avoid using tobacco
- Limit alcohol
- Eat a healthful diet
RESOURCES
The Brain Aneurysm Foundation http://www.bafound.org
National Stroke Association http://www.stroke.org
CANADIAN RESOURCES
Brain Injury Canada http://braininjurycanada.ca
Heart and Stroke Foundation http://www.heartandstroke.com
References
Macdonald RL, Schweizer TA. Spontaneous subarachnoid haemorrhage. Lancet. 2017 Feb 11;389(10069):655-666.
Subarachnoid hemorrhage. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/subarachnoid-hemorrhage. Accessed October 5, 2020.
Revision Information
- Reviewer: EBSCO Medical Review Board Rimas Lukas, MD
- Review Date: 09/2020
- Update Date: 05/25/2021