Stenosis

A stenosis ( plural: stenoses, ) (from Ancient Greek στένωσις, "narrowing") is an abnormal narrowing in a blood vessel or other tubular organ or structure. It is also sometimes called a stricture (as in urethral stricture). The term coarctation is a synonym, but is commonly used only in the context of aortic coarctation.

Restenosis is the recurrence of stenosis after a procedure.

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.

Causes

 * atherosclerosis causes stenotic lesions in arteries.
 * birth defects
 * diabetes
 * 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
 * Calcification

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 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 narrowing

Stenoses/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
 * Stenosing tenosynovitis