Brain Aneurysm: Symptoms, Warning Signs, Causes & Treatment
A brain aneurysm is a condition many people worry about but few understand. Learn the warning signs, what causes aneurysms, and when to seek expert neurological evaluation.
Call 911 immediately. A ruptured aneurysm is a life-threatening emergency.
A sudden, severe headache — often described as the “worst headache of your life” — can be a sign of a ruptured brain aneurysm. Call 911 immediately. Other emergency signs include a stiff neck, sudden vision changes, loss of consciousness, seizure, or sudden weakness or numbness.
The good news is that most brain aneurysms never rupture, and knowing the warning signs can save a life. This guide explains what a brain aneurysm is, the symptoms to watch for, what causes them, and how they're diagnosed and treated.
What Is a Brain Aneurysm?
A brain aneurysm, also called a cerebral aneurysm, is a weak, bulging spot in the wall of a blood vessel in the brain. As blood pumps through the vessel, the weak area can balloon outward, much like a thin spot on a tire or a small berry hanging from a stem.
Many brain aneurysms are small and cause no problems at all. The concern arises if an aneurysm grows, presses on nearby structures, or — in the most serious cases — ruptures and bleeds into or around the brain.
Brain Aneurysm Symptoms
Symptoms depend on whether an aneurysm is unruptured or ruptured.
Symptoms of a Ruptured Brain Aneurysm
A rupture causes bleeding in the brain and comes on suddenly. Call 911 immediately if you or someone else experiences:
- A sudden, extremely severe headache — the “worst headache of your life”
- Nausea and vomiting
- A stiff neck
- Sudden blurred or double vision
- Sensitivity to light
- A drooping eyelid
- Seizure
- Loss of consciousness
- Confusion or sudden weakness
Do not wait, and do not drive yourself — call 911.
Symptoms of an Unruptured Brain Aneurysm
Most unruptured aneurysms cause no symptoms. A larger one that presses on nearby nerves or brain tissue may cause warning signs such as:
- Pain above or behind one eye
- A dilated or enlarged pupil
- Double vision or other vision changes
- Numbness or weakness on one side of the face
- A drooping eyelid
Warning Signs Not to Ignore
Some people experience a “sentinel” or warning headache days or weeks before a rupture, caused by a small leak of blood. Any sudden, unusually severe, or unexplained headache that is different from your normal headaches deserves immediate medical attention.
When in doubt, treat a sudden severe headache as an emergency.
What Causes a Brain Aneurysm?
Brain aneurysms develop when the wall of a blood vessel becomes weak. This can be present from birth or develop over time. Several factors increase the risk:
- High blood pressure — one of the most important and controllable risk factors
- Smoking — strongly linked to both the development and rupture of aneurysms
- Family history — having a first-degree relative with a brain aneurysm
- Age — aneurysms are more common after age 40
- Sex — women have a somewhat higher risk than men
- Certain inherited conditions, such as polycystic kidney disease and connective tissue disorders
- Heavy alcohol or stimulant/drug use, including cocaine
- Head injury or certain blood vessel diseases
Often, a brain aneurysm results from a combination of these factors rather than a single cause.
How Is a Brain Aneurysm Diagnosed?
Brain aneurysms are diagnosed with imaging that looks at the blood vessels of the brain. Depending on the situation, a doctor may order:
CT Scan
Often the first test, especially in an emergency, to look for bleeding.
CT Angiography (CTA)
A CT scan with contrast dye to visualize blood vessels.
MRI / MRA
Detailed imaging of the brain and its vessels.
Cerebral Angiogram
A specialized X-ray that provides the most detailed view of blood vessels and helps plan treatment.
If you have a strong family history of brain aneurysms or an inherited condition that raises your risk, talk with a neurologist about whether screening imaging is appropriate for you.
Brain Aneurysm Treatment
Treatment depends on the aneurysm's size, location, and whether it has ruptured, as well as your age and overall health.
- Monitoring: Many small, unruptured aneurysms that aren't causing symptoms are watched over time with regular imaging, blood pressure control, and quitting smoking.
- Surgical clipping: A neurosurgeon places a tiny metal clip at the base of the aneurysm to stop blood flow into it.
- Endovascular coiling / flow diversion: A less invasive procedure using a catheter to place coils or a stent that seals off the aneurysm.
Treatment of a brain aneurysm is performed by neurosurgeons and interventional specialists. As neurologists, our role is to evaluate symptoms, arrange the right imaging, help manage risk factors like blood pressure, and coordinate prompt referral when treatment is needed.
Brain Aneurysm Survival Rate
Outcomes vary widely. An unruptured aneurysm that is monitored or treated has an excellent outlook, and many people live their entire lives without one ever causing harm.
A ruptured aneurysm is far more serious — but survival and recovery improve dramatically with fast emergency treatment. This is exactly why recognizing the warning signs and calling 911 immediately matters so much. Every minute counts.
Can You Prevent a Brain Aneurysm?
You can't change your age, sex, or family history, but you can meaningfully lower your risk — especially the risk of rupture — by managing what's within your control:
- Keep your blood pressure under control
- Don't smoke — and get help quitting if you do
- Limit alcohol and avoid stimulant drugs
- Eat a heart-healthy diet and stay physically active
- Manage related conditions like high cholesterol with your doctor
- Know your family history and discuss screening if aneurysms run in your family
When to See a Neurologist
While a sudden, severe headache is an emergency, there are good reasons to see a neurologist on a non-emergency basis, including:
- Frequent, severe, or changing headaches
- A strong family history of brain aneurysms
- Vision changes, eye pain, or unexplained neurological symptoms
- A previously discovered, unruptured aneurysm that needs monitoring
At Mir Neurology, our board-certified neurologists evaluate headaches and neurological symptoms, arrange the appropriate imaging, help you manage risk factors, and coordinate care with neurosurgical specialists when needed.
Request an evaluation or call (301) 797-7600.
Serving Western Maryland & the Tri-State Area
Mir Neurology serves patients across Western Maryland, the Eastern Panhandle of West Virginia, and South-Central Pennsylvania, with offices in Cumberland and Hagerstown.
Maryland
Cumberland, Hagerstown, LaVale, Frostburg, Cresaptown, Hancock, Williamsport, Smithsburg, Boonsboro
West Virginia
Martinsburg, Keyser, Romney, Berkeley Springs, Paw Paw
Pennsylvania
Waynesboro, Greencastle, Chambersburg, Mercersburg
Cumberland office: 924 Seton Dr Suite C, Cumberland, MD 21502 — Mon–Sat, 7:30 AM – 4:30 PM
Hagerstown office: 11110 Medical Campus Rd Unit 151, Hagerstown, MD 21742 — Mon–Fri, 7:30 AM – 5:00 PM
Frequently Asked Questions
What does a brain aneurysm headache feel like?
A ruptured aneurysm causes a sudden, severe headache that peaks within seconds and is often called the “worst headache of your life.” It's different from a typical headache or migraine. Any sudden, severe headache like this is a 911 emergency.
Can you have a brain aneurysm for years without knowing?
Yes. Most unruptured brain aneurysms cause no symptoms and can be present for years. Many are discovered by chance during imaging done for another reason.
Are brain aneurysms hereditary?
Family history is a risk factor. If a parent, sibling, or child has had a brain aneurysm, your risk is higher, and screening may be recommended. Certain inherited conditions also raise the risk.
Is a brain aneurysm the same as a stroke?
They're related but not the same. A ruptured aneurysm can cause a type of stroke, called a hemorrhagic stroke, by bleeding into or around the brain. Not all strokes are caused by aneurysms.
What is the survival rate of a brain aneurysm?
Unruptured aneurysms that are monitored or treated have an excellent outlook. A ruptured aneurysm is serious, but rapid emergency treatment greatly improves the chances of survival and recovery.
Worried About Headaches or Your Aneurysm Risk?
Mir Neurology provides expert headache and neurological evaluations in Cumberland and Hagerstown.