Elevated blood creatinine can indicate impaired kidney function.

“creatinine is a breakdown product of creatine creatine phosphate is in your muscles people with more muscle are gonna have more creatine creatine is excreted uh in the proximal tubule and is filtered in glomerulus we measure it in the blood so it gives us a sense of the kidney function because it tells us how well the kidney is functioning to pass creatinine from the blood through the glomerulus into the kidney tubules and excreted in the proximal tubule then excreting your urine so if you're not getting rid of a lot of creatinine the inference that we make in medicine is that your kidneys aren't working well okay”