I was found to have a brain aneurysm: What does it mean, and what happens next?
Most brain aneurysms found by chance have not ruptured. What the report says, who reviews it, and when to call 911.
By Dr. Martin Roberto Casas MartínezSep 1, 20268 min read
In this article
- What is a brain aneurysm, and what does “unruptured” mean?
- Why was it found if I don’t feel anything?
- What does my imaging report say?
- Who should review my images, and what happens next?
- When should I call 911?
- How do I prepare for my first consultation?
- Frequently asked questions
- What should I ask at the consultation?
- References
Summary: Being told you have a brain aneurysm means that an area of an artery in your brain is weak and bulges outward. Most aneurysms found incidentally are unruptured, which is not the same as a rupture. The next step is an assessment with a vascular neurosurgery specialist, who will review your imaging, medical history, and risk factors to determine whether monitoring or treatment is appropriate. If you develop a sudden, extremely severe headache or other sudden symptoms, call 911 before anything else.
Receiving a report that says “brain aneurysm” can be frightening, partly because the word is associated with emergencies. However, when an aneurysm is found during imaging done for another reason, it is generally unruptured, and the next step is an organized assessment process whose priority depends on the individual case. This guide explains the steps: what the report says, who should review it, which warning signs require emergency care, and how to prepare for your consultation.
What is a brain aneurysm, and what does “unruptured” mean?
A brain aneurysm is a weak area in the wall of an artery in the brain that bulges outward, like a thin-walled balloon. It is called “unruptured” when that wall has not opened or allowed blood to escape; most incidental findings are of this type.
Ruptured and unruptured are categories based on whether the aneurysm has ruptured; symptoms are a separate consideration, because an unruptured aneurysm can also cause problems if it presses on nearby structures.
By shape, the most common is the saccular aneurysm (round, attached to the artery by a narrow neck, also called a “berry” aneurysm); another type is fusiform (the widening involves the entire circumference of the artery). Separately, by cause, there is the mycotic aneurysm, associated with an infection that weakens the wall.
The NINDS (the U.S. institute for neurological disorders) also describes them by size: small (less than 11 mm), large (11 to 25 mm), and giant (more than 25 mm). These are descriptive categories; decisions about what to do do not depend on size alone.
Why was it found if I don’t feel anything?
Because most unruptured aneurysms do not cause symptoms while they are small and not growing. They are often discovered on an MRI or CT scan ordered for another reason, such as a headache, a head injury, or a routine checkup.
An incidental finding describes how the aneurysm was discovered, not its current status. An imaging report alone cannot tell you whether the aneurysm is stable or has grown; that requires interpretation by a specialist along with your medical history and, in many cases, additional tests.
Some larger aneurysms or aneurysms in certain locations can press on nearby nerves and cause a drooping eyelid, double vision, pain behind the eye, a dilated pupil, or facial numbness. If you have any of these symptoms, mention them at your consultation.
What does my imaging report say?
The report describes the aneurysm’s location (which artery), size in millimeters, shape (saccular or fusiform), and sometimes additional findings or a recommendation for another test. It does not take your symptoms or medical history into account; that interpretation is the specialist’s role.
The test may be an MRI, CT angiography (a CT scan with contrast that shows the arteries), MR angiography, or catheter angiography. In addition to location, size, and shape, the report may mention terms such as “infundibulum” (an anatomical variation that is not always an aneurysm) or recommend a more detailed test.
A practical tip: request the original images on a disc or in digital format, not just the printed report. The specialist needs to review the images directly and, if prior studies are available, compare them to see whether anything has changed.
Who should review my images, and what happens next?
An assessment should be done by a vascular neurosurgery or endovascular therapy specialist, who will evaluate the aneurysm’s shape, its relationship to nearby arteries, and your risk factors. Next steps may include additional imaging, monitoring with imaging, or a proposed treatment, depending on the individual case.
The doctor who ordered the test—a neurologist, internist, or general practitioner—is usually the one who shares the news, but assessing the aneurysm requires a specialist trained in these conditions. In some cases, the specialist may request an additional test, such as catheter angiography, to see the aneurysm in greater detail. This does not necessarily mean the situation is urgent; it is often part of the diagnostic process.
According to the NINDS, not all brain aneurysms need treatment: for very small aneurysms without symptoms, periodic monitoring may be recommended. When treatment is considered, options include open surgery and endovascular techniques (performed from inside the artery); the benefits and risks of each option are explained during the consultation. The priority and type of care depend on each person’s clinical situation.
When should I call 911?
Call 911 immediately if you develop a sudden, extremely severe headache unlike any other, or experience loss of consciousness, sudden confusion, weakness on one side of the body, difficulty speaking, or sudden vision changes. These symptoms may indicate a rupture and cannot wait.
According to the American Stroke Association and MedlinePlus, a ruptured aneurysm may cause:
- •A sudden, very severe headache, sometimes described as “the worst headache of my life,” with or without nausea, vomiting, or a stiff neck.
- •Loss of consciousness, sudden confusion, or extreme drowsiness.
- •Sudden weakness or numbness in the face, an arm, or a leg; sudden difficulty speaking or understanding.
- •Sudden vision changes or a pupil that suddenly becomes dilated.
If you have these warning signs, do not wait to see if they improve or try to schedule an appointment: immediate care is the priority. Gradual changes, such as an eyelid that begins to droop or progressively worsening double vision, also require prompt attention because they may indicate that the aneurysm is growing or pressing on a nerve. Tell your treating doctor that same day, and if you cannot reach them, go to the emergency department.
How do I prepare for my first consultation?
Gather the original images on a disc or in a digital file, the written report, any previous head or neck studies, your medication list, and your family history of aneurysm or brain hemorrhage. Bringing this information allows the specialist to compare the results and guide you with a fuller picture.
Also note when your symptoms began, if you have any, and bring a record of your blood pressure if you measure it at home. The specialist will ask about risk factors such as smoking, high blood pressure, and family history.
There is no single answer that applies to every aneurysm. The decision to monitor, treat endovascularly, or operate depends on the aneurysm’s characteristics, your overall health, your age, and your preferences. The specialist explains the options and risks, and you take part in the decision with sufficient information.
Frequently asked questions
Do all brain aneurysms need treatment?
No. According to the NINDS, not all aneurysms need treatment; for very small aneurysms without symptoms, periodic imaging surveillance may be recommended. The decision considers size, location, shape, growth, age, and overall health, and is made individually with the specialist.
What factors increase the risk of an aneurysm rupturing?
According to the NINDS, growth between scans is the greatest risk factor, followed by size; location, a previous rupture, a family history of rupture, smoking, and high blood pressure also matter. The specialist assesses that risk individually.
Can a brain aneurysm be present from birth?
Yes. It may be present from birth as a defect in the artery wall, or develop over a person’s lifetime due to factors such as high blood pressure or smoking. Finding it in adulthood does not indicate how long it has been there.
What should I ask at the consultation?
For sudden symptoms like those described, call 911 first. For your consultation with the specialist, these questions may help:
- •Where is my aneurysm, what size and shape is it, and what does that mean in my case?
- •Do I need another test before making a decision?
- •What are my options—monitoring or treatment—and what are the risks of each?
- •Which symptoms should I report right away, and which can wait until the consultation?
For non-urgent questions or to request an individual assessment, you can contact the office.
Informational notice: This content is for informational purposes and does not replace a medical consultation or constitute a diagnosis.
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