A brain aneurysm (AN-yoo-riz-um) is a bulge or ballooning in a blood vessel in the brain. It often looks like a berry hanging on a stem.
A brain aneurysm can leak or rupture, causing bleeding into the brain (hemorrhagic stroke). Most often a ruptured brain aneurysm occurs in the space between the brain and the thin tissues covering the brain. This type of hemorrhagic stroke is called a subarachnoid hemorrhage. This requires immediate medical attention, as it can be life threatening.
A sudden, severe headache is the key symptom of a ruptured aneurysm. This headache is often described as the “worst headache” ever experienced.
Common signs and symptoms of a ruptured aneurysm include:
- Sudden, extremely severe headache
- Nausea and vomiting
- Stiff neck
- Blurred or double vision
- Sensitivity to light
- A drooping eyelid
- Loss of consciousness
In some cases, an aneurysm may leak a slight amount of blood. This leaking (sentinel bleed) may cause only a: Sudden, extremely severe headache. A more severe rupture often follows leaking.
An unruptured brain aneurysm may produce no symptoms, particularly if it’s small. However, a larger unruptured aneurysm may press on brain tissues and nerves, possibly causing:
Pain above and behind one eye
A dilated pupil
Change in vision or double vision
Numbness of one side of the face