What is an aneurysm?
An aneurysm occurs when pressure causes a weak point in a blood vessel to balloon. The small sac or bulge created is known as an aneurysm.
When people talk about aneurysms, they are most often referring to brain aneurysms, also called cerebral or intracranial aneurysms, but aneurysms can also form in the abdomen or, more rarely, in the chest.
Not all brain aneurysms rupture. In fact, about 1 in 50 people in the United States has an unruptured aneurysm, and 50-80% of aneurysms don’t burst during a person’s life.
Early and accurate diagnosis of a brain aneurysm is crucial. Unruptured aneurysms can often be treated before they burst. In the case of a ruptured aneurysm, immediate care may save a person’s life and lessen brain damage.
Signs of an aneurysm
Small and unchanging aneurysms generally produce no symptoms and are often discovered in the course of imaging or tests for other conditions. When an aneurysm does produce symptoms, the symptoms depend on the aneurysm’s location and on whether or not the aneurysm has ruptured.
A ruptured aneurysm is almost always accompanied by sudden and severe pain in the region of the aneurysm.
An unruptured, growing brain aneurysm may lead to any of the following head-related symptoms:
- Pain above or behind the eye
- Partial facial paralysis or a drooping eyelid
- Double vision (also called diplopia) or other vision changes
- A dilated pupil
A ruptured brain aneurysm will almost always cause a sudden and severe headache. You may also experience the following:
- Double vision
- Stiff neck
- Sensitivity to light (also called photosensitivity)
- Cardiac arrest
- Loss of consciousness
An aneurysm that has not ruptured fully may also begin to leak, which will cause a headache and should be treated immediately.
Abdominal aortic aneurysm
An unruptured aneurysm in the abdomen produces symptoms only about one-fourth of the time. The most common sign of an abdominal aortic aneurysm is pain, either sharp or dull, in the abdomen, groin, lower back, or chest.
If your pain is sudden and severe, this may be a sign that the aneurysm is about to burst and it should be considered a medical emergency.
If the aneurysm ruptures, you may experience any of the following in addition to localized pain:
Thoracic aortic aneurysm
An aneurysm in the chest is rare and is usually related to certain genetic disorders or a personal history of aortic valve problems. People with first-degree relatives who have had a thoracic aortic aneurysm should be screened.
In addition to pain, you may experience any of the following symptoms as the thoracic aortic aneurysm leaks, expands, or ruptures:
Types of aneurysms
Aneurysms are generally classified according to their formation. There are three types:
This kind of aneurysm bulges out on all sides of the artery.
This type of aneurysm forms as a result of an infection that weakens the arteries.
Doctors also classify aneurysms according to their size: small, large, or giant.
Causes of an aneurysm
Aneurysms may arise suddenly after severe trauma, but they more often result from the gradual weakening of arteries throughout a person’s life. Certain conditions or behaviors increase your risk of developing an aneurysm:
- High blood pressure (also called hypertension)
- Family history
- Congenital abnormality (birth defect)
- Head trauma
- Alcohol abuse
- Drug abuse, particularly of cocaine
Gender can also play a role. Women are more likely to develop brain aneurysms and have brain aneurysms rupture. However, men are more likely to develop abdominal aneurysms.
Certain other disorders can also increase your chance of developing an aneurysm. These include:
When to see the doctor for an aneurysm
You should see a doctor if you experience any signs of an aneurysm.
In the event of a ruptured aneurysm, call emergency medical services rather than having someone drive you to the hospital. First responders may be required to give you lifesaving treatment in the emergency vehicle.
Diagnosing an aneurysm
Aneurysms are detected through medical imaging and screening, including:
In the case of a suspected brain aneurysm, doctors may also perform a cerebrospinal fluid (CBF) analysis. In a cerebrospinal fluid analysis, cerebrospinal fluid (fluid that flows within and around the brain and spinal cord) is gathered through a lumbar puncture and then tested to detect the presence of bleeding.
Treatments for an aneurysm
Some aneurysms may only require monitoring and risk-factor reduction. In other cases, surgery may be required.
For an aortic aneurysm, the aorta (a large artery in the body) may be replaced with a fabric or plastic graft. Brain aneurysms are surgically treated with clipping, the placement of a metal clip across the base of the aneurysm so that no blood can enter.
Health Solutions From Our Sponsors
Brain Aneurysm Foundation: "Statistics and Facts."
Brain Aneurysm Foundation: "Treatment."
Brain Aneurysm Foundation: "Warning Signs/Symptoms."
Harvard Health Publishing: "Understanding aneurysms."
Johns Hopkins Medicine: "Abdominal Aortic Aneurysm."
MedlinePlus: "Thoracic aortic aneurysm."
National Institute of Neurological Disorders and Stroke: "Cerebral Aneurysms Fact Sheet."