Which statement best contrasts edema with lymphedema?

• A. Edema is swelling due to dehydration.
• B. Lymphedema is caused by high blood sugar.
• C. Edema from venous insufficiency is the result of infection.
• D. Edema is swelling from fluid accumulation. Lymphedema involves impaired lymph drainage and protein-rich fluid.

Answer: (D)

Distinguishing edema from lymphedema depends on the cause and the fluid involved. Edema refers to swelling caused by an excess of fluid in the interstitial spaces; it’s a broad term used for swelling from many different processes, not tied to a single mechanism like dehydration alone. Lymphedema, on the other hand, is a specific type of edema resulting from impaired lymphatic drainage, which leads to accumulation of lymph that is richer in protein than normal interstitial fluid. That protein-rich fluid and the disrupted lymph flow are key features that set lymphedema apart from general edema.

The other statements don’t fit because they misstate the underlying causes or the nature of the fluid. Edema due to dehydration isn’t how edema is defined, and high blood sugar is not the defining cause of lymphedema. Edema from venous insufficiency is driven by increased venous pressure, not infection.