What is an aneurysm?
An aneurysm is a bulge in an artery. It happens from a weak spot in the artery wall. An artery is a blood vessel that carries blood from your heart to the different parts of your body. Veins are the blood vessels that carry blood back to your heart. Veins don't get aneurysms.
Aneurysms can happen in any artery
You might be born with an aneurysm, but most happen when you're older because you have hardening of the arteries (atherosclerosis Atherosclerosis In people with atherosclerosis, patchy deposits of fatty material (atheromas or atherosclerotic plaques) develop in the walls of medium-sized and large arteries, leading to reduced or blocked... read more
)
Aneurysms sometimes suddenly burst open or cause blood clots that block the artery
Doctors do surgery to close or remove the aneurysm
Sometimes doctors can put a small metal coil in the aneurysm to close it without doing surgery

You can also have an aneurysm in your aorta Overview of Aortic Aneurysms and Aortic Dissection The aorta, which is about 1 inch (2.5 centimeters) in diameter, is the largest artery of the body. It receives oxygen-rich blood from the left ventricle of the heart and distributes it to all... read more . Your aorta is the main artery that carries blood from your heart.
What causes aneurysms?
An aneurysm may be caused by:
A weakness in the artery wall that you were born with
A buildup of fatty material inside your arteries (atherosclerosis Atherosclerosis In people with atherosclerosis, patchy deposits of fatty material (atheromas or atherosclerotic plaques) develop in the walls of medium-sized and large arteries, leading to reduced or blocked... read more
, also called hardening of the arteries)
An injury to an artery from a knife or gunshot
A bacterial or fungal infection in your artery—this can happen from injecting illicit drugs, such as heroin
What are the symptoms of an aneurysm?
Some aneurysms don't cause any symptoms. Symptoms depend on where the aneurysm is in your body and on its size.
An aneurysm in your leg usually doesn't cause symptoms unless a blood clot forms in the aneurysm. If you have a blood clot, it may leave the aneurysm and block blood flow in your foot and make it painful, numb, and cool.
An aneurysm in your neck can form a blood clot that travels to your brain and cause a stroke Stroke A stroke is a sudden brain problem that happens when a blood vessel in your brain either gets blocked or breaks open and bleeds. As with all organs in the body, the brain needs oxygen and nutrients... read more .
An aneurysm in your brain may cause a headache. If a brain aneurysm bursts it will cause bleeding around your brain (called a subarachnoid hemorrhage Subarachnoid Hemorrhage A subarachnoid hemorrhage is bleeding in the space that surrounds the brain. It's a medical emergency that can be fatal or cause long-lasting brain damage. Subarachnoid hemorrhage happens when... read more ) that causes a severe headache and can be fatal.
Sometimes an aneurysm gets infected. Infected aneurysms cause pain and swelling.
How can doctors tell if I have an aneurysm?
Sometimes doctors can feel a throbbing mass in your artery by examining you. They may also do:
CT angiography CT angiography Computed tomography (CT) is a type of medical imaging that combines a series of x-rays to create cross-sectional, detailed images of internal structures. In computed tomography (CT), which used... read more
or magnetic resonance angiography Magnetic Resonance Imaging (MRI) of the Heart With magnetic resonance imaging (MRI), a powerful magnetic field and radio waves are used to produce detailed images of the heart and chest. This expensive and sophisticated procedure is used... read more (MRA)
How do doctors treat aneurysms?
Aneurysms in different locations are treated differently.
Aneurysms in the brain are treated with surgery to close the aneurysm with a metal clip, or to place a metal coil into the aneurysm through a small tube (catheter) passed through an artery in your neck.
Aneurysms in your arm or leg are treated with surgery to remove the aneurysm and replace it with a piece of artificial blood vessel (graft). Sometimes doctors can put a graft in through a catheter passed through your artery.
You'll get antibiotics or antifungal medicines for an infected aneurysm.