Stenosis

The word stenosis simply means narrowing. In cardiovascular medicine, it most often describes the progressive restriction of an artery's internal channel — usually caused by the buildup of plaque (atherosclerosis) on the artery walls. As plaque accumulates, the space through which blood can flow shrinks. The body can partially compensate at first, but significant stenosis eventually reduces blood delivery to the tissues the artery serves.

Carotid stenosis — narrowing of the carotid arteries in the neck — is one of the leading risk factors for stroke, because these vessels supply blood to the brain. Coronary artery stenosis reduces blood flow to the heart muscle, causing chest pain (angina) during exertion and raising the risk of heart attack. Renal artery stenosis affects the kidneys, and peripheral arterial stenosis can reduce circulation to the legs. Each location produces different symptoms, but the underlying mechanism is similar: restricted flow through a narrowed passage.

How much narrowing is present matters greatly. Mild stenosis may require only lifestyle changes and medication to slow its progression. Moderate stenosis is monitored closely. Severe stenosis — typically defined as greater than 70 percent reduction in vessel diameter — may be treated with a procedure to widen the artery, such as angioplasty with stenting, or in some cases surgery. Imaging studies including ultrasound, CT angiography, and MR angiography allow physicians to measure the degree of narrowing accurately.

Stenosis often progresses silently for years before causing a noticeable event like a stroke or heart attack. This is why vascular screening — particularly carotid ultrasound for people with risk factors like hypertension, high cholesterol, or a history of smoking — can be so valuable. Catching significant narrowing before it causes an event creates an opportunity to intervene.

Managing the underlying contributors to stenosis — controlling blood pressure, lowering LDL cholesterol, quitting smoking, and staying physically active — can slow its progression substantially. Medications such as statins and antiplatelet drugs also play an important role. Understanding stenosis as a modifiable, treatable condition rather than an inevitable one is an empowering shift in perspective.