Condition: Subarachnoid Hemorrhage (SAH)

Also called: Hemorrhagic Stroke

What is a hemorrhagic stroke?

A stroke happens when there is a loss of blood flow to part of the brain. Your brain cells cannot get the oxygen and nutrients they need from blood, and they start to die within a few minutes. This can cause lasting brain damage, long-term disability, or even death.

There are two main types of strokes, ischemic and hemorrhagic. A hemorrhagic stroke is less common but often more severe. It occurs when a blood vessel in the brain bursts, causing bleeding (hemorrhage) in or around the brain. This bleeding increases pressure inside the skull and damages brain tissue. Within minutes, brain cells begin to die.

What are the types of hemorrhagic stroke?

Hemorrhagic strokes are classified by where the bleeding happens:

• Intracerebral hemorrhage. Bleeding occurs directly into the brain tissue. This is the most common type of hemorrhagic stroke.
• Subarachnoid hemorrhage. Bleeding occurs in the space between the brain and the thin layers of tissues covering it. This often happens when a weak spot in an artery (called an aneurysm) bursts on the brain's surface.

What causes hemorrhagic stroke?

Common causes include:

• Aneurysm. A bulge or "ballooning" in a weakened artery wall that can burst.
• Arteriovenous malformation (AVM). A tangled group of abnormal blood vessels that can rupture inside the brain.
• High blood pressure (hypertension). Over time, it can weaken blood vessel walls and increase the risk of them breaking open.
• Head trauma. Brain injury can cause bleeding.

What are the symptoms of a hemorrhagic stroke?

Stroke symptoms often happen suddenly. They include:

• Sudden numbness or weakness of the face, arm or leg (especially on one side of the body)
• Sudden confusion, trouble speaking, or understanding speech
• Sudden trouble seeing in one or both eyes
• Sudden trouble walking, dizziness, loss of balance or coordination
• Sudden severe headache with no known cause

The F.A.S.T. test can help you remember what to look for if you think someone is having a stroke. Think "FAST" and look for:

• Face drooping on one side when smiling.
• Arm weakness occurs when the arms are raised, and one arm drifts downward.
• Speech is slurred or strange.
• Time to call 911.

How is a hemorrhagic stroke diagnosed?

To make a diagnosis, your health care provider may do a physical exam, ask about your symptoms and medical history, and use imaging tests to check for bleeding in your brain.

How is hemorrhagic stroke treated?

It is important to treat strokes as quickly as possible. For a hemorrhagic stroke, the first step is to find the cause of bleeding in the brain and stop it. Treatment may involve medicines or, in some cases, surgery to stop the bleeding or relieve pressure on the brain.

After the stroke, rehabilitation can help people recover lost abilities and regain independence.

Can a hemorrhagic stroke be prevented?

The best way to prevent stroke is by making heart-healthy lifestyle changes to lower your risk. If lifestyle changes aren't enough, your provider may prescribe medicine to help manage your risk factors.

NIH: National Institute of Neurological Disorders and Stroke