An<unk>  is an outward bulging, likened to a bubble or balloon, caused by a localized, abnormal, weak spot on a blood vessel wall.<unk> s may be a result of a hereditary condition or an acquired disease.<unk> s can also be a nidus (starting point) for clot formation (thrombosis) and embolization. The word is from ,<unk> a, "dilation", from ἀνευρύνειν, aneurynein, "to dilate". As an<unk>  increases in size, the risk of rupture, which leads to uncontrolled bleeding, increases. Although they may occur in any blood vessel, particularly lethal examples include<unk> s of the Circle of Willis in the brain, aortic<unk> s affecting the thoracic aorta, and abdominal aortic<unk> s.<unk> s can arise in the heart itself following a heart attack, including both ventricular and atrial septal<unk> s. There are congenital atrial septal<unk> s, a rare heart defect.
Aneurysm
Baker's cyst
Coma
Angioma
Hematoma
Vascular tumor
Gliosis
Pseudoaneurysm