Hello Darlene, you haven t mentioned whether this value was out of a single measurement or was it confirmed on a second test? Serum potassium can rise for many reasons. Kidney problems can cause it as your doctor already told you. Endocrine problems may cause it as well. Drugs cause it very often (particularly angiotensin converting enzyme inhibitors and angiotension receptor blockers but also potassium sparing diuretics etc). Potassium can also rise by excessive use of supplements (check your supplements - they may contain potassium). Other less common causes exist as well - the list could go on and on. A possible clue to the cause can be provided by a basic chemistry panel and urinalysis. Kidney problems can be spotted by elevated creatinine values, abnormal results on urinalysis etc. Sodium will probably be abnormal in related endocrine disorders. I could not provide the full list here - the text would be enough to fill a whole book! I d like to finish my answer by drawing your attention to possible errors that lead to a false diagnosis of hyperkalemia (elevated serum potassium). When the blood is drawn laboriously, red blood cells may break and release potassium. This excessive potassium will be detected by the lab and the result will be falsely high. In any case a high potassium level warrants investigation, so I suggest you follow your doctor s advice. I hope I ve given you some insight about potassium disorders! If you have any more questions you can ask me again. I ll be glad to answer! Kind Regards!