What term refers to the swelling of a body part, potentially caused by trauma or illness?

The term that refers specifically to the swelling of a body part, often due to fluid accumulation, is "edema." Edema can occur as a result of various factors, including trauma, infection, or underlying health conditions. It involves the retention of fluids in the interstitial space of the tissues, leading to noticeable swelling.

Inflammation, while associated with swelling, refers to the body's immune response to injury or infection, which may include redness, heat, and pain along with swelling. Swelling is a general term that describes the enlargement of a body part; however, it does not specifically indicate the cause or mechanism behind that enlargement. Hematoma refers to a localized collection of blood outside blood vessels, usually caused by trauma, leading to a specific type of swelling that contains fluid and clotted blood.

In this context, edema is the most precise term describing the phenomenon of swelling due to fluid accumulation, making it the correct choice.