Patient education: Subarachnoid hemorrhage (The Basics)

What is a subarachnoid hemorrhage? — A subarachnoid hemorrhage is a type of stroke that causes bleeding around your brain. "Hemorrhage" is the medical term for bleeding.

If you have a subarachnoid hemorrhage, the bleeding happens in a part of your head called the "subarachnoid space." This is the area between your brain and the thin layer of tissue that covers it (figure 1).

The most common cause of a subarachnoid hemorrhage is a bulging blood vessel that bursts. The medical term for this is a "ruptured aneurysm."

A subarachnoid hemorrhage is life threatening, especially when it is caused by a ruptured aneurysm. Many people who have a subarachnoid hemorrhage die from it.

What are the symptoms of a subarachnoid hemorrhage? — The main symptom is:

●Sudden and very painful headache. It can feel like the worst headache you ever had.

Other symptoms include:

●Passing out (losing consciousness)

●Having a seizure

●Nausea or vomiting

●Stiff neck

●Being bothered by bright light

Is there a test for subarachnoid hemorrhage? — Yes. If your doctor suspects you have had a subarachnoid hemorrhage, they can order 1 or more of these tests:

●CT scan of your head – This test uses a type of X-ray to take pictures of the inside of your head. If there is bleeding around your brain, a CT scan will likely show it.

●Lumbar puncture (sometimes called a "spinal tap") – During this procedure, a doctor puts a needle into your lower back and takes out a small sample of spinal fluid. Spinal fluid is the fluid that surrounds the brain and spinal cord. If this fluid has more red blood cells than usual, you could have a subarachnoid hemorrhage. This test is done if the CT scan does not show bleeding but your doctor still thinks you might have a subarachnoid hemorrhage.

●Other imaging tests – If the CT scan or lumbar puncture shows a subarachnoid hemorrhage, your doctor might do other tests to see if the cause is a ruptured aneurysm. These tests include:

•CT angiography (often called "CTA") or magnetic resonance angiography (often called "MRA") – These tests use special types of CT and MRI scans to create pictures of the blood vessels in the brain. Doctors use a dye injection in CTA, and sometimes in MRA. The dye is a chemical that makes blood vessels show up more clearly.

•Catheter angiography – For this test, the doctor puts a thin tube into a large artery in your leg. Then the doctor moves the tube into the large blood vessels that carry blood to your head. Next the doctor injects a dye into the tube that shows up on an X-ray. The dye can show problems with the blood vessels in the brain.

How is a subarachnoid hemorrhage treated? — Most people who have a subarachnoid hemorrhage go to the intensive care unit (ICU) of a hospital for treatment. In the hospital, the doctor might:

●Give medicines and other treatments to reduce the brain damage caused by the bleeding

●Give medicines to lower blood pressure if it is too high

●Stop "anticoagulant" medicines. These include aspirin, warfarin (brand name: Jantoven), and similar medicines that are used to prevent or treat blood clots. If you take any of these medicines, your doctor might give you treatments to help your blood clot. This can help stop bleeding.

●Do tests to figure out the cause of the bleeding

●Watch the pressure in the brain to make sure it does not get too high

If an aneurysm caused the subarachnoid hemorrhage, doctors must do surgery or another procedure to keep the bleeding from happening again. Depending on the size and location of the aneurysm, they might:

●Put tiny coils in the aneurysm. (This is done during a catheter angiography procedure.)

●Do surgery to put a small clip on the aneurysm.

After a subarachnoid hemorrhage, most people stay in the ICU for a few days, weeks, or sometimes longer. Doctors and nurses watch for problems such as:

●Irregular heartbeat

●Seizures

●Blood clots in the legs

●Lung infections

●Electrolytes out of balance – Electrolytes are chemicals in the body that must be present in the right amounts for your body to work correctly

●Vasospasm – This is a medical term meaning that the arteries in the brain spasm, causing them to suddenly get narrower. This can happen in the first few days and weeks after a subarachnoid hemorrhage. It can lead to a stroke.

What will my life be like? — A subarachnoid hemorrhage is very serious. Many people die from this type of stroke. Many people who survive – but not all – have long-lasting health problems afterwards.

People who have severe subarachnoid hemorrhages can have certain health problems later, such as:

●Memory problems

●Mood changes or problems with emotions

●Thinking problems

●Trouble speaking, walking, or doing other activities

For some people, these problems can be disabling. For others, they might not exist or cause only mild problems.

More on this topic

Patient education: Stroke (The Basics)
Patient education: Hemorrhagic stroke (The Basics)
Patient education: Brain aneurysm (The Basics)

Patient education: Hemorrhagic stroke treatment (Beyond the Basics)
Patient education: Stroke symptoms and diagnosis (Beyond the Basics)