High Creatinine Level in Blood

A couple of years ago I had a test come up positive for a high level of creatinine in my blood. A medical assistant called to give me results of several of my tests and she didn't seem to understand what it meant that my level was high. I didn't either. Now I am searching for a real diagnosis for my surmounting health problems. One problem I have is that I urinate a lot. I drink a lot of fluids too (all kinds). When I was younger I used to get UTIs and yeast infections a lot as well. I also was in the hospital once for painful bladder spasms.

I just had an appt. with an endocrinologist and tomorrow will have some blood tests where I think they will be doing this test again. I am starting to wonder if I might have an endocrine related problem. Perhaps there is something wrong with my kidneys? What types of diseases would you see this in?