A 28-year-old female is admitted with a 3-day history of facial swelling, foamy urine, and bilateral lower-extremity edema. Laboratory results reveal serum albumin 1.8 g/dL, total protein 4.2 g/dL, serum cholesterol 320 mg/dL, and urinalysis showing 4+ proteinuria. The client asks the nurse why her face and legs are so swollen when she has been drinking less fluid than usual. Which response by the nurse best explains the pathophysiological mechanism responsible for the client's edema?
- "Your kidneys are retaining too much sodium and water because they are inflamed and not filtering properly."
- "Protein loss in urine lowers blood protein and plasma oncotic pressure, allowing fluid to move into tissues and cause edema."
- "An allergic reaction is causing your blood vessels to become leaky, allowing fluid to escape into the surrounding tissue."
- "Your heart is not pumping efficiently, causing fluid to back up into your legs and face."