Kidney failure edema often flares at what time of day?

• A. Evening
• B. Midday
• C. Night
• D. In the morning

Answer: (D)

Fluid distribution and excretion vary with time of day, and kidney failure disrupts the ability to handle that fluid. When you lie down to sleep, gravity stops pulling fluid into the legs and tissue fluid can accumulate in the face and other areas. At the same time, the kidneys are less able to excrete the excess water, so the edema builds up overnight. On waking and becoming active, fluid shifts and urine production increase, so the noticeable edema is greatest in the morning and improves as the day goes on. That diurnal pattern—more pronounced edema in the morning due to nocturnal fluid retention and partial mobilization with activity—explains why morning is the typical time edema flares in kidney failure.