General education
Why kidney testing includes blood and urine
A blood test and a urine test answer different questions about the kidneys. Neither one replaces the other.
General education, not medical advice. Talk with a clinician about your own results.
Two different questions
Kidney testing usually asks two things: how well the kidneys filter, and whether protein is leaking into the urine. The first is answered by a blood test; the second by a urine test.
Because they measure different things, a normal result on one does not rule out a problem the other would show.
The blood test
eGFR is estimated from a blood measurement and reported as a number. It is the familiar filtration estimate, and it is often part of a routine panel. It says nothing direct about protein in the urine.
The urine test
A urine albumin-to-creatinine ratio measures albumin, a protein, against creatinine in the same sample. It can be raised while eGFR is still in the normal range, which is why it adds information the blood test alone cannot provide.
This test is frequently not ordered, and that gap is part of why kidney disease can go unnoticed.
Who interprets them
A clinician interprets both results together with the person's history, medicines and earlier measurements. One result in isolation may need repeat assessment before it is treated as a lasting finding. Ask your clinician what your results mean for you.
Practice this case
The missing testA synthetic record with eGFR present and the urine result missing. Decide what the record supports, then read the explanation.Open the case →Sources
Background reading for the general medical statements in this guide. They do not describe NephroSense AI or its performance.