An aneurysm is a weak spot in the wall of a blood vessel that may cause an abnormal bulge.
A brain (cerebral) aneurysm is a bulging, weak area in the wall of an artery that supplies blood to the brain. In most cases, a brain aneurysm causes no symptoms and goes unnoticed. In rare cases, the brain aneurysm ruptures, releasing blood into the skull and causing a stroke. The following risk factors may increase your risk for an aneurysm or, if you already have an aneurysm, may increase your risk of it rupturing: 1  Family history. 2  People who have a family history of brain aneurysms are more likely to have an aneurysm than those who don't. Brain aneurysms develop as a result of thinning artery walls. Aneurysms often form at forks or branches in arteries because those sections of the vessel are weaker. Although aneurysms can appear anywhere in the brain, they are most common in arteries at the base of the brain. 1  Symptoms. 2  Risk factors.  Causes of a brain aneurysm. Brain aneurysms are caused by a weakness in the walls of blood vessels in the brain. There are several reasons why this may happen, although an exact cause is not always clear. The brain requires a large supply of blood delivered via four main blood vessels that run up the neck and into the brain. An aneurysm is an abnormal widening or ballooning of an artery due to weakness in the wall of the blood vessel. Aneurysms are dangerous because they may burst, spilling blood in the area surrounding the blood vessel. The disease can occur in the aorta, in a blood vessel in the brain, or in a peripheral blood vessel.  Cerebral aneurysms, also known as intracranial or brain aneurysms, occur most commonly in the anterior cerebral artery, which is part of the circle of Willis. This can cause severe strokes leading to death. The next most common sites of cerebral aneurysm occurrence are in the internal carotid artery. Aneurysms are a result of a weakened blood vessel wall, and can be a result of a hereditary condition or an acquired disease. Aneurysms can also be a nidus for clot formation (thrombosis) and embolization. Knowledge center. An aneurysm occurs when part of a blood vessel (artery) or cardiac chamber swells, - either the blood vessel is damaged, or there is a weakness in the wall of the blood vessel. As blood pressure builds up it balloons out at its weakest point. An aneurysm can occur in any part of the body. They tend to occur most commonly on the wall of the aorta-the large trunk artery that carries blood from the left ventricle of the heart to branch arteries. The aorta goes down through the chest and into the abdomen, where it divides into the iliac arteries (two branches). 1 An aneurysm occurs when part of a blood vessel or cardiac chamber swells. 2  An aneurysm can occur in any part of the body, though they often occur on the wall of the aorta. 3  The two main types of aneurysms are aortic aneurysms and cerebral aneurysms. 4  Aneurysms are most common in men and people over 65 years of age. An aneurysm can occur in any part of the body. They tend to occur most commonly on the wall of the aorta-the large trunk artery that carries blood from the left ventricle of the heart to branch arteries. The aorta goes down through the chest and into the abdomen, where it divides into the iliac arteries (two branches). A cerebral aneurysm (also known as an intracranial or intracerebral aneurysm) is a weak or thin spot on a blood vessel in the brain that balloons out and fills with blood. The bulging aneurysm can put pressure on a nerve or surrounding brain tissue.  Aneurysms can occur in any blood vessel, with examples including aneurysms of the circle of Willis in the brain, aortic aneurysms affecting the thoracic aorta, and abdominal aortic aneurysms. Aneurysms can also occur within the heart itself. As an aneurysm increases in size, the risk of rupture increases. A ruptured aneurysm can lead to bleeding and subsequent hypovolemic shock, leading to death. Aneurysms are a result of a weakened blood vessel wall, and can be a result of a hereditary condition or an acquired disease. Aneurysms can also be a nidus for clot formation (thrombosis) and embolization. Overview. An aneurysm is a weak spot in the wall of a blood vessel that may cause an abnormal bulge. The bulge can rupture and cause internal bleeding. Although it can occur in any blood vessel, aneurysms are most common in the brain, the aorta, the legs, and spleen.
http://www.webmd.com/brain/tc/brain-aneurysm-topic-overview http://www.mayoclinic.org/diseases-conditions/brain-aneurysm/basics/causes/con-20028457 http://www.nhs.uk/Conditions/Aneurysm/Pages/Causes.aspx http://www.healthgrades.com/conditions/aneurysm https://en.wikipedia.org/wiki/Aneurysm http://www.medicalnewstoday.com/articles/156993.php http://www.medicalnewstoday.com/articles/156993.php http://www.ninds.nih.gov/disorders/cerebral_aneurysm/detail_cerebral_aneurysms.htm https://en.wikipedia.org/wiki/Aneurysm http://www.healthline.com/health/aneurysm
what is aneurysm caused by