The three most useful starting points are eGFR, creatinine, and urine albumin, often reported as UACR.
eGFR is an estimate of how well the kidneys are filtering blood.
Creatinine is a blood marker used to calculate that estimate and to follow kidney function over time.
UACR looks for albumin leaking into the urine, which can be an early sign that the kidney filter is under stress.
These tests do not answer the same question. That is why one number can look stable while another is already showing a problem.
Why one abnormal result is not enough
A lab value by itself rarely tells the full story. A mildly low eGFR can reflect dehydration or a temporary shift. A creatinine slightly above range may mean something different in a muscular younger person than in an older smaller one. A single urine albumin result may need confirmation before it is treated as persistent kidney damage.
What matters more is the pattern: what has changed, what has stayed stable, and whether blood pressure, diabetes, medications, or illness help explain the result.
Where to start
If you are trying to make sense of your report, start with the basics. Learn what eGFR, creatinine, and UACR are each measuring. Then ask which one was abnormal, whether repeat testing is needed, and whether the result fits a longer trend.