High levels of potassium and high levels of bun in the blood are indicators of some degree of kidney dysfunction.
The most common cause of high potassium in the blood is kidney disease. A healthy blood potassium level falls between 3.6 and 4.8 milliequivalents per liter. When the kidneys are not working properly, they do not remove potassium from the blood efficiently, causing levels to increase above 4.8 milliequivalents per liter.
A healthy bun usually falls between 7 and 20 milligrams per deciliter. If your bun level exceeds 20 milligrams per deciliter, it can indicate kidney disease.