A patient with acute renal dysfunction has coffee-colored urine. This finding most strongly suggests involvement of which process?

A patient with acute renal dysfunction has coffee-colored urine. This finding most strongly suggests involvement of which process?

• A. Glomerular injury
• B. Dehydration
• C. Diabetes mellitus
• D. Biliary obstruction

Answer: (A)

Coffee-colored urine signals blood in the urine (hematuria). When the glomerular filtration barrier is damaged, red blood cells leak into the urine, giving it a dark, coffee-brown color. This points to an intrarenal, glomerular process such as glomerulonephritis or nephritic-type injury. Dehydration can darken urine through concentration but doesn’t introduce blood. Diabetes mellitus-related kidney disease develops more gradually and is not typically defined by a sudden coffee-colored urine. Biliary obstruction darkens urine from bilirubin, not from red blood cells. So the finding most strongly suggests glomerular injury.

Coffee-colored urine signals blood in the urine (hematuria). When the glomerular filtration barrier is damaged, red blood cells leak into the urine, giving it a dark, coffee-brown color. This points to an intrarenal, glomerular process such as glomerulonephritis or nephritic-type injury. Dehydration can darken urine through concentration but doesn’t introduce blood. Diabetes mellitus-related kidney disease develops more gradually and is not typically defined by a sudden coffee-colored urine. Biliary obstruction darkens urine from bilirubin, not from red blood cells. So the finding most strongly suggests glomerular injury.