What Is Stenosis? - Definition, Types & Symptoms

Instructor: Virginia Rawls

Virginia has a master' degree in Education and a bachelors in Sports Medicine/athletic Training

Stenosis is the medical term for a stricture, or narrowing, of a piece of anatomy, and it can be found in many of the bodily systems. This lesson is going to dive into the term 'stenosis' and look at what this condition is, the different types that exist, and the symptoms.

Understanding Stenosis

Your cardiovascular system is a specialized and complex webbing that contains the heart, arteries, veins and capillaries. Even thought this system is highly efficient, there are numerous conditions that can cause it to not function to its fullest potential. One of those conditions is called stenosis. Stenosis is an abnormal stricture or narrowing in the body.

Lets try to make this easy to picture using a couple of examples:

  • Imagine that you are going outside to water your flowers. You turn on the faucet, unwrap the hose and pull the hose to your flowerbed. You turn the sprayer on, but only a little trickle of water comes out. You look down and realize that you are standing on the hose. When you pull your foot off of the hose, the water comes out full force. When you stepped on that hose, you caused a 'stenosis' of the hose.
  • One morning, you are brushing your teeth and notice that the water is not draining out of the sink. You let the water run for a minute then turn it off. You can hear a small trickle of water in the pipes, so you know water is draining, but it takes a long time for the sink to fully empty. When the sink empties, you remove the stopper and find a big hairball. You remove the hairball and turn on the sink. The water empties just fine - problem solved! This hairball was causing a 'stenosis' of the pipes under your sink.

Types of Cardiovascular Stenosis

Like I mentioned before, the circulatory system is made up of the heart, arteries, veins and capillaries. It is critical that blood move through all of these components quickly and efficiently. If there is a stricture in any of them, it could have an extremely negative effect on the body.

Stenosis can occur in the vascular system a few different ways. When the valves of the heart have stenosis, it usually can be pinpointed to one of two reasons:

  1. It could be caused by a congenital defect, or a defect caused during fetus development.
  2. It may occur when the valves become thicker than normal - if the valves are thicker, they cannot open and close properly. Think about our example of the garden hose.

When the vessels have stenosis, this also could be the result of a congenital defect or caused by plaque. Plaque is a hard substance that can build up in your vessels over time. This is usually due to diets high in fats and cholesterol. When plaque builds up in your vessels, it decreases the amount of blood that can move through them as well as the speed at which the blood is pumped. Think about our example of the hairball in the sink.

In the following sections, let's take a look at common examples of stenosis throughout the circulatory system.

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