"A lot of people potentially could be walking around and not even know that they have an aneurysm." 

4Neurosurgeon Dr. Mark Bain with Cleveland Clinic says not all aneurysms cause symptoms. Larger, 5steadily growing ones may cause pain above and behind the eye, 6numbness, weakness, 7paralysis on one side of the face, a 8dilated pupil in the eye, or vision changes. 

Bain says not all aneurysms need treatment. 

"A lot of aneurysms are actually 9fairly safe. People don't think they're safe, but the 10rupture rates are very, very low." 

There are aneurysms that do 11pose a risk of rupture. Bain says those should be treated. When an aneurysm 12bursts, it's extremely dangerous and causes a sudden, severe headache. Emergency medical attention is needed immediately. 

"That way they can 13stabilize you, make sure your blood pressure is well controlled. And then typically they'll contact a place that can treat a brain aneurysm." 

Bain says it's also important to know the risk factors including family history of an aneurysm, untreated high blood pressure, cigarette smoking and age. 

He says treatments have come a long way and can go in through a leg or wrist artery without an 14incision. 

"Patients wake up without any pain and they're able to go home the next day."