Subarachnoid hemorrhage is a type of stroke that occurs when a blood vessel ruptures. Blood quickly fills the area immediately surrounding the brain and spinal cord. This space contains the cerebrospinal fluid. The fluid cushions and protects the brain and spinal cord.
This life-threatening condition requires emergency medical care. The hemorrhage may increase the pressure around the brain. It can interfere with the brain's ability to function.
Subarachnoid hemorrhage may be caused by:
Factors that may increase your chance of developing subarachnoid hemorrhage include:
- Past history of aneurysms
- High Blood Pressure, which increases the risk of aneurysm rupture
- Alcohol use disorder
- Cocaine use
- Disorders associated with weakened blood vessels, including polycystic kidney disease, fibromuscular dysplasia, or connective tissue disorders
- Estrogen deficiency
- Family history of aneurysms
Symptoms may include:
- A very sudden, severe headache
- Brief loss of consciousness
- Nausea and vomiting
- Weakness on one side of your body
- Unexplained numbness or tingling
- Slurred speech or other speech disturbance
- Visions problems, such as double vision, blind spots, or temporary vision loss on one side
- Stiff neck or shoulder pain
If you have these symptoms, call for emergency medical services right away. Early care can decrease the amount of damage to brain.
Your doctor will ask about your symptoms and medical history. A physical exam will be done. Your cerebrospinal fluid may need to be tested. This can be done with a lumbar puncture.
Imaging tests evaluate the brain and surrounding structures. This can be done with:
Subarachnoid hemorrhage is a serious condition. It typically requires initial treatment in the intensive care unit. Despite treatment, many people with this condition die.
The aim of treatment is to stop the bleeding, limit damage to the brain, and reduce the risk of it occurring again. If bleeding results from a cerebral aneurysm, a doctor will usually attempt to stop it using various techniques. Patients receive medication to ensure proper blood flow to the rest of the brain. Absolute bed rest is needed to prevent additional bleeding. After the situation is stabilized, patients undertake a vigorous rehabilitation program.
Aneurysms present since birth cannot be prevented. Because they are so rare, doctors do not advise screening for them. If an unruptured aneurysm is discovered by chance in a young person, the doctor may do surgery.
Avoiding smoking and controlling blood pressure can reduce the risk of a rupture if an aneurysm exists. Wearing a seatbelt and using a helmet can also reduce the risk of subarachnoid hemorrhage from head trauma.
The Brain Aneurysm Foundation
National Stroke Association
Brain Injury Association of Canada
Heart and Stroke Foundation of Canada
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Last reviewed June 2015 by Rimas Lukas, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.