What does extravasation refer to in a medical context?

Extravasation specifically refers to the process where fluids, particularly blood or other bodily fluids, leak out of their intended vessel and into the surrounding tissue. This term is often used in a medical context to describe situations where intravenous fluids or drugs escape from the veins, which can lead to tissue damage and complications. When fluids extravasate, they can cause swelling, pain, and inflammation in the surrounding tissue due to the accumulation of those fluids outside of the vascular system.

The other options describe different medical phenomena. Inflammation occurs as a response to injury or infection, clotting relates to the process that stops bleeding, and tissue expansion due to fluid accumulation describes conditions like edema rather than the specific action of fluids leaking from vessels. Understanding these different definitions helps clarify the unique meaning of extravasation within medical terminology.