The video discusses BUN, creatinine, cystatin C and eGFR, and asks whether a high result means kidney disease. This article explains what these results can and cannot show. Do not try to lower a number without understanding its cause.
BUN measures urea nitrogen; creatinine comes from creatine breakdown
BUN can change with urea production and other factors, so it is not a stand-alone measure of kidney function. Creatinine is also related to muscle mass and other health conditions. Clinicians consider trends, related test results and the person’s health context rather than relying on the reference range printed on a lab report alone.
eGFR and cystatin C can add context
Estimated glomerular filtration rate (eGFR) is calculated from blood-test results and other relevant information. In some cases, an equation using both creatinine and cystatin C may estimate filtration more accurately, particularly when creatinine alone may be less reliable. The choice of test depends on the clinical question and the care team’s judgment.
Do not change fluids or protein to lower a result on your own
An abnormal result can have several causes. Restricting fluids or protein, or stopping a medicine without professional guidance, may be harmful. Bring previous results and a medication list to a healthcare appointment so a clinician can review trends, kidney function and whether urine tests are needed.