What is a subarachnoid hemorrhage?
A subarachnoid hemorrhage is bleeding in the space between your brain and the membrane
that covers it. Most often, it occurs when a weak area in a blood vessel (aneurysm)
on the surface of the brain bursts and leaks. The blood then builds up around the
brain and inside the skull. This increases pressure on the brain. It can cause brain
cell damage, life-long problems, and disabilities.
When an aneurysm is located in the brain, it's called a cerebral, intracerebral, or
intracranial aneurysm. A cerebral aneurysm often develops over a long period of time
and may not cause any symptoms before it bursts or ruptures. Most aneurysms develop
after age 40.
What causes a subarachnoid hemorrhage?
A subarachnoid hemorrhage may cause a type of stroke called a hemorrhagic stroke.
This type of stroke causes bleeding inside the brain. It is different from an ischemic
stroke, which is caused by a blood clot.
This bleeding may go through the brain tissue and leak into the area outside the brain.
This area is called the subarachnoid space. This can be life threatening. The blood
from the hemorrhage can compress or displace vital brain tissue. A severe hemorrhage
can cause a coma. Or it can leave you paralyzed.
What are the symptoms of a subarachnoid hemorrhage?
Common symptoms include:
Loss of consciousness
Nausea or vomiting
Severe headache, the worst headache pain you've ever had that feels different from
Confusion and trouble concentrating
Sensitivity to light
These symptoms may look like other health problems. Get medical care right away if
you have these symptoms.
A brain aneurysm can lead to a subarachnoid hemorrhage. A brain aneurysm can cause these symptoms:
How is a subarachnoid hemorrhage diagnosed?
If you have symptoms of a subarachnoid hemorrhage, a healthcare provider might use
several tests to diagnose it:
MRI scan. This test uses large magnets, radio waves, and a computer to make detailed images
of the brain. It doesn't use X-rays.
CT scan. This test uses X-rays and a computer to make horizontal (axial) images of the brain.
CT scans are more detailed than general X-rays.
Angiogram.During this test, contrast dye is injected in the blood vessel and then X-rays are
taken to assess blood flow through them.
Spinal tap. In this test, a special needle is placed into the lower back, into the spinal canal.
The pressure in the spinal canal and brain can be measured. A small amount of cerebrospinal
fluid (CSF) can be removed. The CSF is checked for blood.
A diagnosis of a cerebral aneurysm isn't usually made until a subarachnoid hemorrhage
has already occurred.
How is a subarachnoid hemorrhage treated?
A subarachnoid hemorrhage is a medical emergency. Immediate treatment is needed to
help reduce the risk for permanent brain damage. The main goal is to stop the bleeding.
Often, a healthcare provider may do surgery to place a small clip on the blood vessel
to stop blood from leaking into the brain.
Some types of aneurysms can be treated with an endovascular coil. This procedure is
done by either a radiologist or a neurosurgeon. It is done with a tiny incision in
your groin. A thin tube called a catheter is put through the incision into the artery
in your leg. It is pushed up to the artery in your head that is bleeding. Recovery
time from this type of treatment is much shorter than traditional surgery. But not
all aneurysms can be treated this way. Your healthcare provider can determine if you
are a candidate for this treatment after doing an angiogram.
Part of the long-term treatment of a subarachnoid hemorrhage involves addressing any
risk factors that may have helped trigger the hemorrhage. One of the biggest risk
factors is smoking. If you smoke, you need to quit. Gaining better control of conditions
such as diabetes, high cholesterol, or high blood pressure are also important. Keeping
a healthy body weight and eating a healthy diet can also reduce your risk.
What are possible complications of a subarachnoid hemorrhage?
After a subarachnoid hemorrhage, serious complications can occur. Swelling in the
brain (hydrocephalus) is 1 of the possible problems. It's caused by the buildup of
CSF and blood between the brain and skull, which can increase the pressure on the
brain. A subarachnoid hemorrhage can also irritate and damage the brain's other blood
vessels, causing them to tighten. This reduces blood flow to the brain. As blood flow
becomes affected, another stroke can happen. This can lead to even more brain damage. In
serious cases, the bleeding may cause permanent brain damage, paralysis, or coma.
When should I call my healthcare provider?
The sooner the bleeding in the brain is controlled, the better the outlook. Get emergency
medical help if you have any signs such as:
Severe headache; the worst headache pain that you have ever had
Nausea and vomiting with the headache
Confusion and trouble concentrating
Sensitivity to light with the headache
Key points about a subarachnoid hemorrhage
A subarachnoid hemorrhage means that there is bleeding in the space that surrounds
It is life threatening and a medical emergency.
It usually occurs in people over 40 years of age.
It usually presents as the worst headache of your life and is often followed by loss
Seek immediate medical treatment if any of the above symptoms affect you or a loved
Tips to help you get the most from a visit to your healthcare provider:
Know the reason for your visit and what you want to happen.
Before your visit, write down questions you want answered.
Bring someone with you to help you ask questions and remember what your provider tells
At the visit, write down the name of a new diagnosis and any new medicines, treatments,
or tests. Also write down any new instructions your provider gives you.
Know why a new medicine or treatment is prescribed and how it will help you. Also
know what the side effects are and when you should report them to your healthcare
Ask if your condition can be treated in other ways.
Know why a test or procedure is recommended and what the results could mean.
Know what to expect if you do not take the medicine or have the test or procedure.
If you have a follow-up appointment, write down the date, time, and purpose for that
Know how you can contact your provider if you have questions.