What is a stenosis?

Quick Answer
An abnormal narrowing or constriction of a canal or passageway in the body that is caused by the buildup of cholesterol, fats, or other substances (called plaque); the swelling or overgrowth of cells, tissue, or an organ; or a deformity.
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Causes and Symptoms

Stenosis can occur in many areas of the body, such as an artery, a heart valve, or the vertebral (spinal) canal. It may stem from many causes, depending on the area affected. In an artery, stenosis occurs with the buildup of cholesterol, fats, or other substances, called plaque. A stenotic heart valve can be a congenital birth defect or the result of an infection (endocarditis), rheumatic fever, or aging. The septum, or dividing wall in the heart, can enlarge and lead to an abnormally small ventricle, or heart chamber. Spinal stenosis is caused by a deteriorating or herniated disk, arthritis, tissue enlargement inside the spinal canal, deformities of the spinal column (Paget’s disease), or an injury.

Symptoms of this disorder relative to an artery, heart valve, or ventricle include high blood pressure, pain or tightness in the chest (angina pectoris), shortness of breath, dizziness or fainting with exertion, fatigue, palpitations (rapid heartbeat), or a heart murmur. In more severe cases, it can develop into a heart attack or stroke. The symptoms of spinal stenosis include back, neck, leg, or buttocks pain or numbness that worsens with standing or exercising.

Treatment and Therapy

Medication is commonly used to treat or relieve the symptoms caused by a stenosis. Blood thinners such as aspirin and warfarin allow easy passage of blood through a stenosed area to lower the risk of high pressure. Cholesterol-lowering medications slow the buildup of plaque in the artery. Antibiotics help repair damaged heart valves, with a long course and high dosage used if the cause is infectious endocarditis. Finally, anti-inflammatory medications or steroid injections are the first line of treatment for spinal stenosis.

A number of interventions can be used to correct this disorder. Balloon angioplasty flattens plaque buildup, while valvuloplasty widens the valve opening. A stent, or wire mesh tube, is often inserted following an angioplasty to hold the artery open. One alternative is atherectomy, in which a laser or rotary shaver breaks up the plaque. If a patient has multiple severely stenosed arteries, then coronary artery bypass surgery may be recommended. Finally, artificial heart valve replacement surgery or corrective surgery for spinal stenosis may be warranted.


Dorland’s Illustrated Medical Dictionary. 32nd ed. Philadelphia: Elsevier/Saunders, 2012.

Dugdale, David C., III, Shabir Bhimji, and David Zieve. “Pulmonary Valve Stenosis.” MedlinePlus, June 7, 2012.

Dugdale, David C., III, Michael A. Chen, and David Zieve. “Aortic Stenosis.” MedlinePlus, June 4, 2012.

“Questions and Answers about Spinal Stenosis.” National Institute of Arthritis and Musculoskeletal and Skin Diseases, Jan. 2013.