I have had a low Anion gap since July, 2015. Three separate times - A 5 (with a BUN of 21), A 2 (BUN of 20) and now a 5 (BUN 21). I have protein in my urine off and on, same with microscopic hematuria. I get UTI's easily and I have scaring on my left kidney, a 3 cm cyst on my right. Spine pain, however my MRI has been pretty good with only a mild bulge at L-4/L5. I am tired all the time, get nausea off and on on a regular basis. retain fluid easily in my hands and sometimes, ankles. I generally feel crappy on a regular basis. I'm studying for boards and my memory is for crap. I seem to get sick pretty frequently any more. (I am a Ultrasound tech, 23 years now) Should I see a nephrologist?