@rosebackyard Welcome to Mayo Clinic Connect. You ask what you should do with high creatinine, nitrogen [BUN] and phosphorous levels. First, you talk to your doctor to get their input on the entire test. And you look at previous test results to compare them. One set of results is not usually valuable to make a diagnosis, it is best to look at a trend. There are additional values to take into consideration, also.

The cause of higher than normal values could very well be hydration status at the time of a lab draw, or current/recent infection, medication changes, lifestyle/diet changes, other health conditions your have. Think about all of this and prepare questions for your medical team.
Ginger