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:
Symptoms may include:
If you have these symptoms, call for emergency medical services right away. Early care can decrease the amount of damage to the 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 from 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 Canada
Heart & Stroke Foundation
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Last reviewed May 2016 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.