Stenosis (from Ancient Greekστενός (stenós) 'narrow') is the abnormal narrowing of a blood vessel or other tubular organ or structure such as foramina and canals. It is also sometimes called a stricture (as in urethral stricture).[3]
Stricture as a term is usually used when narrowing is caused by contraction of smooth muscle (e.g. achalasia, prinzmetal angina); stenosis is usually used when narrowing is caused by lesion that reduces the space of lumen (e.g. atherosclerosis).[4] The term coarctation is another synonym,[5] but is commonly used only in the context of aortic coarctation.[6][7]
Restenosis is the recurrence of stenosis after a procedure.[8]
Stenoses of the vascular type are often associated with unusual blood sounds resulting from turbulent flow over the narrowed blood vessel. This sound can be made audible by a stethoscope, but diagnosis is generally made or confirmed with some form of medical imaging (such as ultrasound).[10]