What is "edema" characterized by?

Edema is characterized by puffy swelling of tissue resulting from the accumulation of fluid in the interstitial spaces of the body. This condition occurs when there is an imbalance in the forces that regulate fluid movement in and out of blood vessels and tissues. Factors such as inflammation, injury, certain medical conditions, or even prolonged inactivity can lead to this excess fluid build-up, causing localized or generalized swelling. The noticeable puffy appearance is a direct result of this fluid retention, making it the defining feature of edema.

The other options do not accurately describe edema. Dryness of skin refers to a different dermatological condition, while loss of appetite and rapid weight loss are symptoms that may indicate other underlying health issues but are not associated with fluid retention or swelling in tissues. Thus, the defining characteristic of edema remains the swelling caused by fluid accumulation.