Embolism

An embolism is the blockage of a blood vessel by an embolus, a detached intravascular mass (solid, liquid, or gaseous) that is carried by the bloodstream to a site distant from its point of origin. The embolus travels through the circulatory system until it reaches a vessel that is too small to allow its passage. This obstruction can cause ischemia (reduced blood flow) and infarction (tissue death) in the area supplied by the blocked vessel.

Common types of emboli include:

• Thromboemboli: The most common type, consisting of a dislodged thrombus (blood clot). These often originate in the deep veins of the legs (deep vein thrombosis, DVT) and travel to the lungs, causing a pulmonary embolism (PE).
• Fat Emboli: Occur when fat globules enter the bloodstream, typically after a long bone fracture or liposuction.
• Air Emboli: Air bubbles that enter the circulation. This can occur during surgery, intravenous procedures, or trauma.
• Amniotic Fluid Emboli: A rare but serious complication of childbirth where amniotic fluid enters the maternal circulation.
• Septic Emboli: Infected material, such as bacteria or pus, that breaks off from an infected site (e.g., endocarditis) and travels through the bloodstream.
• Tumor Emboli: Fragments of a tumor that break off and travel through the bloodstream, potentially leading to metastasis.
• Foreign Body Emboli: Various foreign materials (e.g., talc, catheter fragments) that enter the bloodstream.

The consequences of an embolism depend on the size and location of the blocked vessel. A large pulmonary embolism can be life-threatening, while a small embolism in a peripheral vessel may only cause localized pain or discomfort. Diagnosis often involves imaging techniques such as CT scans, ultrasound, or angiography. Treatment typically aims to dissolve or remove the embolus, and to prevent further clot formation with anticoagulant medications.