Potassium Handling in the Kidney

Potassium Filtration and Reabsorption

• Potassium is initially filtered at the glomerulus, and in individuals with normal kidney function, potassium is reabsorbed in the proximal tubule and loop of Henle, with less than 10% of filtered potassium reaching the distal nephron, according to the American College of Physicians, as reported by the Mayo Clinic Proceedings 1

Factors Affecting Potassium Excretion

• Increased urine flow enhances potassium secretion in the distal tubule, and increased sodium delivery to the distal nephron promotes potassium secretion, as stated by the Mayo Clinic Proceedings 1

Potassium Balance in Disease States

• In chronic kidney disease, the remaining functional nephrons adapt by increasing fractional potassium excretion to maintain serum potassium levels, and this adaptive mechanism generally prevents hyperkalemia until eGFR falls below 15 mL/min per 1.73 m², as reported by the National Kidney Foundation, based on information from the Mayo Clinic Proceedings 2