What is an aneurysm?

An aneurysm is a bulging, weak area in the wall of a blood vessel. It may occur in any blood vessel, but most often develops in an artery rather than a vein. An aneurysm can be categorized by its location, shape, and cause. 

An aneurysm may be found in many areas of the body, such as: 

  • Brain (cerebral aneurysm)
  • Aorta (aortic aneurysm)
  • Neck
  • Intestines
  • Kidney
  • Spleen
  • Blood vessels in the legs (iliac, femoral, or popliteal aneurysm)

 The most common types of an aneurysm is in the aorta. The aorta is the largest artery in the body. The aorta carries oxygenated blood from the heart to the body. A thoracic aortic aneurysm is s type that occurs in the chest cavity. An abdominal aortic aneurysm occurs in the abdomen. 

What causes an aneurysm?

An aneurysm may be caused by
factors that result in the breakdown of the artery wall. The exact cause isn’t fully
known. Atherosclerosis (hardening of the arteries) may be part of the cause.

Other causes of aneurysms are
related to where they occur. Examples may include:

Type of aneurysm

Causes of aneurysms

Abdominal aortic
aneurysm (AAA)

  • Atherosclerosis
    (especially in the part of the abdominal aorta below the kidneys,
    called an infrarenal aortic aneurysm)
  • Genetic disorders
  • Giant cell arteritis (a
    disease that causes inflammation of the temporal arteries and other
    arteries in the head and neck)
  • Infection


  • Congenital (present at
  • High blood
  • Atherosclerosis
  • Head injury

Common Iliac artery

  • Atherosclerosis
  • Pregnancy
  • Infection
  • Injury after lumbar or
    hip surgery

Femoral and
popliteal artery aneurysm

  • Atherosclerosis
  • Injury
  • Congenital

Who is at risk for an aneurysm?

You are at higher risk for an
aneurysm if you have atherosclerosis.

Risk factors you can’t control

  • Older age
  • Male
  • Family history
  • Genetic factors

Risk factors you can control

  • High cholesterol
  • High blood pressure
  • Smoking
  • Diabetes
  • Obesity

What are the symptoms of an aneurysm?

Aneurysms may have no symptoms. If
there are symptoms, they will depend on the location of the aneurysm in the body. Pain
is the most common symptom. This is true no matter where the aneurysm is.

Symptoms that may occur with
different types of aneurysms may include:

Type of aneurysm


Abdominal aortic
aneurysm (AAA)

Constant pain in
abdomen, chest, lower back, or groin area


Sudden severe
headache, nausea, vomiting, visual disturbance, loss of consciousness

Common iliac

Lower abdominal,
back, or groin pain

Femoral and
popliteal artery aneurysm

Pulsating of the
artery in the groin (femoral) or on the back of the knee (popliteal),
pain in the leg, sores on the feet or lower legs 

The symptoms of an aneurysm may
look like other medical conditions or problems. See your healthcare provider for more

How is an aneurysm diagnosed?

What tests you’ll need depends on
the location of the aneurysm. Along with a complete medical history and physical exam,
tests for an aneurysm may include:

  • CT scan.
    This imaging test uses X-rays and computer technology to make horizontal
    (axial) images (often called slices) of the body. A CT scan shows detailed images of
    any part of the body, including the bones, muscles, fat, and organs. CT scans are
    more detailed than standard X-rays.
  • MRI.An MRI uses large magnets, radio waves, and a computer to make detailed images
    of organs and structures in the body.
  • Echocardiogram (echo).This procedure evaluates the structure and function of the heart by using sound
    waves recorded on an electronic sensor that makes a moving picture of the heart and
    heart valves.
  • Arteriogram
    This is an X-ray image of the blood vessels used to
    evaluate various conditions, such as aneurysm, stenosis (narrowing of the blood
    vessel), or blockages. A dye (contrast) will be injected through a thin flexible tube
    placed in an artery. This dye will make the blood vessels visible on the X-ray.
  • Ultrasound.
    An ultrasound uses high-frequency sound waves and a computer to create
    images of blood vessels, tissues, and organs. An ultrasound is used to view internal
    organs as they function. And it is used to assess blood flow through various