Can bloodtest determine if i have healthy functioning kidneys or not?

Kidney disease labs: A simple chemistry panel will tell you your BUN and creatinine levels. At 26, you likely have normal kidney function and these would be expected to be normal. I would also have a urine analysis done to see if you have protein or red blood cells in your it. If you have protein in your urine, you will need to have a 24 hour urine collection to see how much you have in it. See a nephrologist.