State the term - Aneurysms

Aneurysms are vascular dilations resulting from localised defects in the elasticity of a vessel. They can be visualised as balloon like expansions of vessels that are usually weak and prone to rupture. Although, aneurysms are usually due to congenital defects, they may also develop from hypertension, arteriosclerosis, embolisms, or infections. A characteristic symptom of an aneurysm is severe headache, which may be present for years, because the aneurysm is exerting pressure on the dura mater, which is richly endowed with pain receptors