- by MEDICJOHN Sep 22, '09Ok, I get SIADH is too much ADH, therefore, the body retains water, which in turn means less water is coming out in urine, thereby making the urine concentrated. What I DONT GET, is how the BUN, Cr, Uric Acid, is then LOW????? I thought, if urine was concentrated, then those would be HIGH???? Or does the BUN etc results indicate how much water is actually CIRCULATING THROUGH the kidney????
- Sep 22, '09 by ElliShayYou are on the right track--the BUN, creatinine, uric acid, etc. are diluted by the excess water... and the lab results reflect the amounts circulating in the plasma--but the decreased levels reflect the disproportionately high amount of water. Check out this link...