Which potassium level is considered to be the riskiest?

Risky potassium : If one has chronic kidney disease, a potassium (k) level of 5.5 may not be a problem. It is not the level of k that is important, it is how quickly it gets to it that is. If a person with normal kidney function has an accident, with a lot of muscle destruction liberating k from muscle, a rise in k from 4.1 to 5.5 in an hour can possibly lead to death. Ask your doctor for more info.