Blood clots in the lungs, known as pulmonary emboli, typically don't form directly in the lungs themselves; instead, they travel there. Here's how it happens:
The Journey of a Blood Clot to the Lungs
The process generally starts with the formation of a blood clot in a deep vein, often in the leg. This is known as a deep vein thrombosis (DVT).
Deep Vein Thrombosis (DVT)
This is where a blood clot forms within a deep vein, usually in the leg.
- Several factors can lead to DVT formation, including:
- Prolonged inactivity (like long flights or bed rest).
- Certain medical conditions, such as cancer.
- Recent surgery.
- Injury to a vein.
- Genetic predisposition to clotting disorders.
The Embolus
Once a clot has formed in a deep vein, it can break away from the vein wall. This detached clot is called an embolus.
Travel to the Lungs
The embolus then travels through the bloodstream, passing through progressively larger veins, eventually reaching the heart. From the heart, the embolus is pumped into the pulmonary arteries, which are the blood vessels that carry blood to the lungs.
Pulmonary Embolism
- The pulmonary arteries are narrower than the blood vessels the embolus has previously travelled through. As the embolus travels to the lungs, it eventually gets lodged in a pulmonary artery, causing a blockage. This blockage is called a pulmonary embolism (PE).
- This blockage can restrict blood flow to the lungs and lead to serious medical issues, such as:
- Reduced oxygen levels in the blood.
- Lung damage.
- Strain on the heart.
- In severe cases, death.
Summary
| Step | Description |
|---|---|
| 1. DVT Formation | A blood clot forms in a deep vein, usually in the leg. |
| 2. Embolus Formation | The clot breaks away from the vein wall. |
| 3. Embolus Travel | The embolus travels through the bloodstream to the heart. |
| 4. Pulmonary Embolism | The embolus is pumped from the heart into the pulmonary artery, becoming lodged in the lungs, blocking blood flow. |
Therefore, blood clots in the lungs are usually the result of an embolus that has travelled from somewhere else in the body, often originating as a DVT in the leg.
