Stenosis
A stenosis (from Ancient Greek στενός, "narrow") is an abnormal narrowing in 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).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). The term coarctation is another synonym, but is commonly used only in the context of aortic coarctation.Restenosis is the recurrence of stenosis after a procedure.

Types
The resulting syndrome depends on the structure affected.
 Examples of vascular stenotic lesions include:

Intermittent claudication (peripheral artery stenosis)
Angina (coronary artery stenosis)
Carotid artery stenosis which predispose to (strokes and transient ischaemic episodes)
Renal artery stenosis The types of stenoses in heart valves are:
Pulmonary valve stenosis, which is the thickening of the pulmonary valve, therefore causing narrowing
Mitral valve stenosis, which is the thickening of the mitral valve (of the left heart), therefore causing narrowing
Tricuspid valve stenosis, which is the thickening of the tricuspid valve (of the right heart), therefore causing narrowing
Aortic valve stenosis, which is the thickening of the aortic valve, therefore causing narrowingStenoses/strictures of other bodily structures/organs include:
Pyloric stenosis (gastric outflow obstruction)
Lumbar, cervical or thoracic spinal stenosis
Subglottic stenosis (SGS)
Tracheal stenosis
Obstructive jaundice (biliary tract stenosis)
Bowel obstruction
Phimosis
Non-communicating hydrocephalus due to aqueductal stenosis
Stenosing tenosynovitis
Atherosclerosis
Esophageal stricture
Achalasia
Prinzmetal angina
Vaginal stenosis
Meatal stenosis

Causes
alcohol
atherosclerosis causes stenotic lesions in arteries.
birth defects
calcification
diabetes
headbanging – as in the case of Dave Mustaine
iatrogenic, e.g. secondary to radiation therapy
infection
inflammation
ischemia
neoplasm – in such cases, the stenosis is often said to be "malignant" or "benign", although this attribute actually refers to the neoplasm itself.
smoking
ureteral
urethral

Diagnosis
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.

See also
Atresia

References
External links
"Tracheal Stenosis Audio and Video". Archived from the original on 2007-01-12.
"Symptoms of Urethral Stricture". 20 May 2011. Archived from the original on July 17, 2016.