Causes of Blood Clots in the Lungs

Instructor: Artem Cheprasov

Artem has a doctor of veterinary medicine degree.

Everything from shortness of breath to death can occur as a result of blood clots in the lungs. Given that, wouldn't you want to know what may cause them? This lesson tells you!

Dangerous Arms & Legs

What in the world about your own arms or legs could possibly hurt you? They're there to help you walk and gesticulate, aren't they? Well, yes. But they can be affected by various problems, ones that can actually end up, in the worst case scenario, killing you! Let's learn what these problems are and how they are connected to blood clots in the lungs.

Pulmonary Emboli

A blood clot in the lung is more properly called a pulmonary embolism, or pulmonary emboli if there are many. An embolus is some sort of plug in a blood vessel that actually originated elsewhere. Here's what this means.

Firstly, emboli are usually (but not always) small pieces of blood clot. A blood clot in the cardiovascular (heart and blood vessel) system of our body is called a thrombus. If a thrombus forms in one part of our body, let's say in the deep veins of our legs, it may break up into smaller pieces. Those smaller pieces, now called emboli, will travel through our blood vessels and into the lungs, causing pulmonary emboli. That's what a pulmonary embolism is, a plug obstructing a vessel in the lungs. This can cause everything from shortness of breath to death, depending on how severe it is and how many there are.

Causes Of Pulmonary Emboli

So, what in the world would cause all of this to happen? Well, let's meet a few people in a hospital so you can learn more about the many causes of pulmonary emboli.

Joel is a man who was recently in a pretty bad car accident. The accident damaged the veins in his arms. Damage to the veins, as a result of something like an accident or even trauma from surgery, will cause a blood clot to form in one or more veins in Joel's arms. That thrombus runs the risk of having an embolus break off and travel to the lungs, where it will cause a pulmonary embolism.

Sarah is a woman who recently broke both her legs. She has had her legs put in a cast, so she uses a wheelchair, which has limited her mobility. The lack of mobility actually increases the risk of clotting in the veins of the legs. This, once again, can cause a thrombus to form in the deep veins of the legs. An embolus may break off and travel to the lungs from there. Immobility can also occur due prolonged lying in bed, such as during a hospital stay, or even by sitting for too long during an airplane ride.

This image shows the formation of a blood clot in a deep vein of a leg, a condition called deep vein thrombosis. This blood clot can then fragment, and an embolus may travel to the lungs to cause pulmonary embolism.

Finally, we meet James. James has a genetic mutation that causes his blood to clot more easily. This is called hypercoagulability, the excessive clotting of blood. Because the blood has a tendency to clot, it can more easily form thrombi and, by extension, emboli. The end result is the same, the lodging of an embolus within the lungs.

Lesson Summary

In summary, the three major reasons for blood clots in the lungs, pulmonary emboli, plural for pulmonary embolism, are:

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