Brain Aneurysm: Warning Signs, Rupture Risk, and How It Is Diagnosed

A brain aneurysm is a bulging, weakened area in a blood vessel in the brain. Many aneurysms do not cause symptoms, but a leak or rupture is a medical emergency that needs urgent care.

Overview

A brain aneurysm is a weak spot in the wall of an artery in the brain that balloons outward. It is sometimes described as a small sac or blister on a blood vessel. Some aneurysms remain stable for years and never cause symptoms, while others can grow, leak, or rupture.

The main concern is rupture, which can lead to bleeding around the brain, most commonly a subarachnoid hemorrhage. This is a serious condition that needs emergency treatment. However, it is also important to know that not every brain aneurysm will rupture, and many are discovered during imaging done for unrelated reasons.

Brain aneurysms can vary in size and shape. Small aneurysms may be monitored, while larger or irregularly shaped ones may carry a higher risk. Decisions about care are individualized and usually involve neurology, neurosurgery, and neuroradiology specialists.

Symptoms and Warning Signs

Many unruptured brain aneurysms do not cause symptoms at all. When they do, symptoms usually happen because the aneurysm is pressing on nearby nerves or brain structures. A person may notice pain above or behind the eye, double vision, a dilated pupil, numbness on one side of the face, or changes in vision.

A leaking aneurysm may cause a sudden and unusual headache, sometimes called a warning headache. This can happen shortly before a full rupture. Any sudden, severe headache that feels different from usual should be assessed urgently by a doctor.

A ruptured brain aneurysm typically causes a very sudden, intense headache that is often described as the worst headache of a person’s life. Other symptoms may include:

• Nausea and vomiting
• Stiff neck
• Sensitivity to light
• Blurred or double vision
• Confusion
• Seizures
• Loss of consciousness

These symptoms are a medical emergency. Immediate evaluation is important because fast treatment can improve outcomes and reduce complications.

Causes and Risk Factors

Brain aneurysms develop when part of an artery wall becomes weakened. The exact reason is not always clear, but both inherited and acquired factors can play a role. Some people are born with a tendency toward weaker blood vessel walls, while others develop risk over time due to health and lifestyle factors.

Important risk factors include smoking and high blood pressure. Both can place extra stress on artery walls and increase the chance that an aneurysm may form, grow, or rupture. Older age, female sex, heavy alcohol use, and stimulant drug use can also increase risk in some people.

Family history matters. A person with two or more close relatives who have had a brain aneurysm may have a higher chance of developing one. Certain inherited disorders, such as polycystic kidney disease and some connective tissue disorders, are also associated with aneurysms.

Sometimes a brain aneurysm is discussed alongside other blood vessel conditions affecting the brain, including stroke and bleeding around the brain. Although these are not the same condition, they may share overlapping emergency symptoms and need prompt medical evaluation.

How Brain Aneurysms Are Diagnosed

Doctors diagnose a brain aneurysm using imaging tests and a careful medical history. If rupture is suspected, the first test is often a CT scan of the head because it can quickly show fresh bleeding. If the CT scan does not explain symptoms but suspicion remains high, further testing may be needed.

Other imaging options include CT angiography, MR angiography, and cerebral angiography. These tests help show the blood vessels in detail and can identify the aneurysm’s size, shape, and exact location. Cerebral angiography is more invasive than CT or MRI, but it can provide very detailed images and is often used when planning treatment.

In some cases, a lumbar puncture may be used if a rupture is strongly suspected but brain imaging does not clearly show bleeding. Doctors may also assess blood pressure, neurological function, and other medical conditions that affect treatment choices.

Advanced MRI scanning and CT imaging are commonly part of the evaluation. When specialized vascular imaging is needed, a team may also use angiography to guide diagnosis and treatment planning.

Treatment Options

Treatment depends on whether the aneurysm has ruptured, how large it is, where it is located, and the person’s age and overall health. For an unruptured aneurysm, doctors weigh the risk of rupture against the risks of treatment. Some aneurysms are best monitored over time with regular imaging and control of risk factors.

When treatment is recommended, the main goals are to prevent bleeding or to stop further bleeding if rupture has already occurred. Common approaches include surgical clipping, in which a neurosurgeon places a small clip across the aneurysm neck, and endovascular treatment, in which specialists reach the aneurysm through the blood vessels to seal it from inside.

Endovascular methods may include coiling, stent-assisted techniques, or flow-diverting devices, depending on the aneurysm’s anatomy. If rupture has occurred, treatment also includes intensive supportive care to manage complications such as rebleeding, blood vessel spasm, hydrocephalus, and neurological injury.

Some patients may require care in units experienced in neurosurgery and brain vascular emergencies. Near the end of the care pathway, Acibadem International’s multidisciplinary specialists and JCI-accredited hospitals also evaluate and treat brain aneurysms for international patients when appropriate.

Prevention and Self-care

There is no guaranteed way to prevent every brain aneurysm, but lowering modifiable risk factors can help protect blood vessels. Stopping smoking is one of the most important steps. Managing blood pressure through regular medical care, prescribed treatment, and healthy habits is also essential.

General vascular health measures can be helpful. These include regular physical activity as advised by a doctor, a balanced diet, good sleep, stress management, and limiting excess alcohol. People should avoid recreational stimulant drugs, which can sharply raise blood pressure and increase the risk of rupture.

For people who already know they have an unruptured aneurysm, self-care mainly means following the treatment plan, attending follow-up imaging appointments, and keeping other health conditions under control. It is also wise to learn the warning signs of rupture and seek emergency care if they occur.

When to See a Doctor

Emergency medical attention is needed for a sudden, severe headache, especially if it is unlike any previous headache. Other urgent symptoms include fainting, seizures, confusion, a stiff neck, vomiting, or sudden changes in vision. These may suggest a ruptured aneurysm or another serious neurological condition.

A non-emergency medical appointment is also appropriate for ongoing symptoms such as double vision, eye pain, a drooping eyelid, or unexplained facial numbness. These symptoms do not always mean a brain aneurysm, but they should be evaluated.

People with a strong family history of aneurysm or certain inherited disorders may wish to discuss screening with a neurologist or other qualified specialist. A doctor can explain whether imaging is appropriate based on personal and family risk.

Frequently asked questions

Can a brain aneurysm exist without symptoms?

Yes. Many brain aneurysms do not cause any symptoms and are found by chance during imaging for another reason. Symptoms are more likely if the aneurysm grows, presses on nearby structures, leaks, or ruptures.

What does a brain aneurysm headache feel like?

A ruptured or leaking aneurysm can cause a sudden, severe headache that reaches maximum intensity very quickly. People often describe it as the worst headache of their life. Because many conditions can cause severe headache, urgent medical evaluation is important.

Are all brain aneurysms dangerous?

Not all brain aneurysms will rupture. Risk depends on factors such as size, location, shape, growth over time, smoking, blood pressure, and family history. A specialist can help estimate risk and recommend monitoring or treatment.

How is a brain aneurysm usually found?

It may be found after symptoms prompt emergency imaging, or incidentally during CT or MRI scans done for another reason. If doctors need a clearer view of the brain’s blood vessels, they may order angiographic imaging.

Can a brain aneurysm be treated without open surgery?

Yes, some aneurysms can be treated using endovascular techniques. These approaches are performed from inside the blood vessels and may include coiling or other devices. Whether this is suitable depends on the aneurysm’s size, shape, and location.

Should family members be screened for brain aneurysm?

Screening may be considered in some families, especially when two or more close relatives have had a brain aneurysm. It may also be discussed for people with certain inherited disorders linked to aneurysm risk. A doctor can advise whether screening is appropriate.

References

• World Health Organization
• National Institute of Neurological Disorders and Stroke
• American Heart Association
• National Health Service
• Brain Aneurysm Foundation

This article is for general information only and is not a substitute for professional medical advice. Please consult a qualified doctor about your individual situation.