kidney physiological measurement free water reabsorption In the physiology of the kidney, free water reabsorption is the volume of water reabsorbed by the blood plasma from the kidney per unit time. A free water reabsorption of zero means the kidney is producing urine isotonic with respect to the plasma. Values greater than zero for free water reabsorption imply that the kidney is producing concentrated urine through the excretion of water with a high level of solutes. slaulede clinical_measurement_ontology renal water absorption kidney water reabsorption renal water reabsorption CMO:0003615 PMID:23955305 nephron water absorption 2020-12-17T17:58:15Z