What is an aneurysm?

An aneurysm occurs when part of an artery wall weakens. In the weakened spot, an abnormally large bulge develops. The bulge can rupture and cause internal bleeding. The cause of an aneurysm is not always known. Some may be caused by aortic disease or injury, while some causes are congenital, meaning people are born with them.
Types of aneurysm
Aneurysms can occur anywhere, but the most common types are:
An aortic aneurysm occurs in the main artery that carries blood to your body. The aorta has a thick wall but trauma or certain conditions can weaken part of the wall. When that happens, the force of the blood can cause an aneurysm. An abdominal aortic aneurysm can grow so big that it splits or ruptures. A split is called a dissection. Splits and ruptures are life-threatening.
Aortic aneurysms can be treated with medicine to slow their growth or with surgery to repair them if they are found before they rupture. Unfortunately, aneurysms often grow to a large size before they are detected. There are two types of aortic aneurysms:
- Abdominal Aortic Aneurysm: This is the most common place for an aortic aneurysm to occur
- Thoracic Aortic Aneurysm: This is a less common type of aortic aneurysm that occurs in the chest area
You may not have any symptoms with an aortic aneurysm. Some symptoms that can occur include a deep, constant pain in the abdomen or side, back pain, or a pulse near your belly button.
Risk factors for aortic aneurysm include:
- High blood pressure
- Hardening of the arteries, also called atherosclerosis
- Inflamed blood vessels
- Infection in the aorta
- Trauma such as a car accident
- Smoking, which is the greatest risk factor
- Age over 65
- Being male
- Being white
- Family history of aneurysms
- Previous aneurysms
Cerebral aneurysm
Cerebral aneurysms usually occur at the base of the brain just inside the skull. Aneurysms can range in size from one-eighth of an inch to one inch. Most cerebral aneurysms do not cause symptoms until they rupture. Some symptoms that can occur include:
- Numbness
- Weakness
- Pain above and behind the eye
- One side of the face being paralyzed
- Dilated pupil
- Vision changes
Risk factors for developing a cerebral aneurysm include:
- A close family member with an aneurysm
- Uncontrolled high blood pressure
- Stimulant drug abuse, especially cocaine or amphetamines
- Age over 40
- Head trauma
- Brain tumor
- Cigarette smoking
Mesenteric artery aneurysm
A mesenteric artery aneurysm is one that occurs in one of the arteries that carry blood to the gastrointestinal tract, which consists of the stomach, intestines, colon, and rectum.
Like other aneurysms, mesenteric artery aneurysms often have no symptoms. When symptoms do occur, they may include:
- Weight loss
- Nausea and vomiting
- Severe abdominal pain after eating
- Bloody bowel movements
- Constipation or diarrhea
Some symptoms may indicate that a mesenteric artery aneurysm is expanding quickly and may rupture. You should seek emergency treatment for the following symptoms:
- Sudden, persistent, and intense abdominal or back pain that feels like a tearing sensation
- Pain that radiates to the back of your legs
- Low blood pressure
- Dizziness and clamminess
- Nausea and vomiting
Risk factors for developing a mesenteric artery aneurysm include:
- Family history
- Being male
- Age over 65
- Smoking
- High blood pressure
- High cholesterol
- Atherosclerosis
- Connective tissue diseases such as Ehlers-Danlos Syndrome

QUESTION
In the U.S., 1 in every 4 deaths is caused by heart disease. See AnswerDiagnosis of aneurysm
Your doctor will listen to your symptoms and conduct a physical exam. Imaging tests will be needed to confirm a diagnosis of an aneurysm. Your doctor will order an angiogram, computerized tomography (CT) scan, or an ultrasound to diagnose you.
Treatment for aneurysm
A ruptured aneurysm is a medical emergency that requires immediate treatment. Go to the emergency room or call 911 if you think you may have one. An unruptured aneurysm may require monitoring and medication.
Your doctor may also need to do surgery to repair an aneurysm by reinforcing the artery wall with a stent. If the aneurysm has ballooned out, the procedure may involve closing off the area with a coiling procedure.
Possible complications and side effects
Ruptured aneurysms can result in death. There are risks associated with surgery to repair an aneurysm as well. These risks include:
- Lung complications
- Damage to the heart
- Death due to circulatory collapse
Surgery is generally done when the risk of the aneurysm rupturing outweighs the risks of surgery.
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Brain aneurysms may rarely cause any warning symptoms before they rupture. Symptoms may occur if the aneurysm is large or if it causes pressure on the structures around it.Abdominal Aortic Aneurysm
Abdominal aortic aneurysm is a ballooning or widening of the main artery (the aorta) as it courses down through the abdomen. Most abdominal aortic aneurysms produce no symptoms. Treatment may include observation or surgical repair.Aneurysm vs Stroke: Which Is Worse?
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A brain aneurysm (cerebral aneurysm) is caused by microscopic damage to artery walls, infections of the artery walls, tumors, trauma, and drug abuse. Symptoms include headache, numbness of the face, dilated pupils, changes in vision, the "worst headache of your life," or a painful stiff neck. Immediate treatment for a brain aneurysm is crucial for patient survival.Stroke vs Aneurysm (Differences and Similarities)
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What is an aneurysm, and how do you know if you have one? An aneurysm, which occurs when blood vessels swell, can be dangerous or even fatal if it ruptures. Learn the signs of an aneurysm, what causes them, how doctors diagnose them, and what you can do if you think you may have an aneurysm.What Does a CT Head Scan Show?
A computerized axial tomography (CAT) or computerized tomography (CT) scan uses a series of X-rays taken at different angles to produce a detailed image of the head and brain. A CT scan is done to study the patient’s skull, brain, jaw, sinuses, and facial bones, and to investigate tumors, head injuries, aneurysms, and other conditions.