URL of this page: //www.nlm.nih.gov/medlineplus/ency/article/001122.htm


An aneurysm is an abnormal widening or ballooning of a part of an artery due to weakness in the wall of the blood vessel.


It is not clear exactly what causes aneurysms. Some aneurysms are present at birth (congenital). Defects in some parts of the artery wall may be a cause.

Common locations for aneurysms include:

  • Major artery from the heart (the aorta)
  • Brain (cerebral aneurysm)
  • Behind the knee in the leg (popliteal artery aneurysm)
  • Intestine (mesenteric artery aneurysm)
  • Artery in the spleen (splenic artery aneurysm)

High blood pressure, high cholesterol, and cigarette smoking may raise your risk of certain types of aneurysms. High blood pressure is thought to play a role in abdominal aortic aneurysms. Atherosclerotic disease (cholesterol buildup in arteries) may also lead to the formation of some aneurysms.

Pregnancy is often linked to the formation and rupture of splenic artery aneurysms.


The symptoms depend on where the aneurysm is located. If the aneurysm occurs near the body's surface, pain and swelling with a throbbing lump is often seen.

Aneurysms in the body or brain often cause no symptoms. Aneurysms in the brain may expand without breaking open (rupturing). The expanded aneurysm may press on nerves and cause double vision, dizziness, or headaches. Some aneurysms may cause ringing in the ears.

If an aneurysm ruptures, pain, low blood pressure, a rapid heart rate, and light-headedness may occur. The risk of death after a rupture is high.

Exams and Tests

The health care provider will perform a physical exam.

Tests used to diagnose an aneurysm include:

  • CT scan
  • Ultrasound
  • Angiogram


Treatment depends on the size and location of the aneurysm. Your doctor may only recommend regular checkups to see if the aneurysm is growing.

Surgery may be done. The type of surgery that is done and when you need it depend on your symptoms and the size and type of aneurysm.

Surgery may involve a large (open) surgical cut. However, some patients may have endovascular embolization. Coils of metal may be inserted into a brain aneurysm to make the aneurysm clot and reduce the risk of rupture. Other brain aneurysms may need to have a clip placed on them to close them off and prevent a rupture.

Aneurysms of the aorta may be reinforced with surgery to strengthen the blood vessel wall.

When to Contact a Medical Professional

Call your health care provider if you develop a lump on your body, whether or not it is painful and throbbing.


Controlling high blood pressure may help prevent some aneurysms. Follow a healthy diet, get regular exercise, and keep your cholesterol at a healthy level to also help prevent aneurysms or their complications.

Do not smoke. If you do smoke, quitting will lower your risk of an aneurysm.


Hauser SC. Vascular diseases of the gastrointestinal tract. In: Goldman L, Schafer AI, eds.Goldman's Cecil Medicine

Isselbacher EM. Diseases of the aorta. In: Goldman L, Schafer AI, eds.Goldman's Cecil Medicine

Zivin JA. Hemorrhagic cerebrovascular disease. In: Goldman L, Schafer AI, eds.Goldman's Cecil Medicine

Update Date 7/27/2014

Related MedlinePlus Health Topics