A pulmonary embolism (PE) is a serious condition that occurs when a blood clot (also called a thrombus) becomes lodged in the lung’s bloodstream. This can happen when a clot that forms in another part of the body, such as the leg, breaks loose and travels to the lung. The clot blocks blood flow to the lung, which can cause damage to the lung tissue and can be life-threatening.
The symptoms of a pulmonary embolism (PE) can vary depending on the size and location of the clot, as well as the patients overall health. Some common symptoms of PE include:
SYMPTOMS
- Shortness of breath: This is the most common symptom and can range from mild to severe. It may get worse with activity or when lying down.
- Chest pain: The pain can be sharp or dull and can be located in the center of the chest, on one side of the chest, or in the back. The pain may also be accompanied by a feeling of tightness or pressure in the chest.
- Rapid heartbeat: The heartbeat may be faster than usual, and the person may feel like their heart is pounding or fluttering.
- Coughing: The person may cough up blood or bloody sputum (phlegm).
- Other symptoms: Fatigue, sweating, feeling lightheaded or dizzy, and fainting.
It’s important to note that some people with PE may have only mild symptoms or no symptoms at all, making it difficult to diagnose.
Pathophysiology
A pulmonary embolism (PE) occurs when a blood clot, usually from the leg, travels through the bloodstream and lodges in one of the pulmonary arteries, blocking blood flow to the lungs. The pathophysiology of a pulmonary embolism involves several processes:
- Formation of a blood clot: Blood clots can form in the veins of the legs or other parts of the body due to several factors, such as immobilisation, surgery, cancer or a genetic predisposition to blood clots.
- Migration of the blood clot: Once a blood clot forms in the leg, it can travel through the bloodstream and reach the lungs, where it can lodge in a small blood vessel, obstructing blood flow and causing a pulmonary embolism.
- Obstruction of blood flow: When the blood clot blocks blood flow to the lungs, it reduces the amount of oxygen that can be exchanged in the lung tissues. This can cause symptoms such as shortness of breath, chest pain, and rapid heartbeat.
- Inflammatory response: When the blood clot lodges in the lung tissue, it triggers an inflammatory response, which can cause further damage to the lung tissue and lead to complications such as pulmonary hypertension or right heart failure.