Does anyone know how the renin levels and the electrolytes are corralated. Meaning if the renin is high should the electrolytes reflect this?  I did a little research on the PRA test and found that it is a very unstable measurement. The reason I am concerned is that my son had a PRA test done on his last lab work. It came back within normal range but on the high end. His electrolytes were perfect. My regular endo got stuck out of town when the WTC tragedy occurred. One other Dr. from my endo's office called and told me that she was aware that my son was not a saltwaster as the DNA said but that she was concerned about the renin being so high that she wanted me to increase his florinef. The next day I got a call from my Dr.'s nurse saying that my Dr. was back in town and had looked at my son's lab results and she said that per the Dr. I should double his cortef and leave the florinef alone. Well, I got suspicious and sent a fax to my Dr.'s office stating that I was not going to change any of my son's meds until I talked to my Dr. in person. To make a long story short,(a little late huh), the Dr. called me on a Sat and said that she didn't want to change any of his meds at all and that everything was fine! I asked her for an explanation. She did give me one. After I got off the phone I realized that I was right to question further and wait to get the exact information otherwise I would have been doubling my sons cortef for no good reason. What a mess that could have turned out to be. Moral of the story trust your doctor but question everything and realize that they are human and can make mistakes too. You just don't want them made with your child.  Back to the renin. I want to find out how reliable of a test it is. Has anyone had problems with these levels? From what I have read about PRA tests it is hard to consider any one accurate since it varies greatly. Thanks for the info in advance.