Kidneys
How well your kidneys filter waste from your blood, plus uric acid.
12 tests explained
Most common tests
- Blood Urea Nitrogen (BUN)BUN is a waste product from protein breakdown that your kidneys clear from the blood, so it gives a rough read on kidney function and hydration.
- BUN/Creatinine RatioA calculated comparison of your BUN with your creatinine that clinicians use as one clue to why a kidney-related number is high or low.
- CreatinineCreatinine is a muscle waste product that your kidneys filter out, so the level in your blood is one of the main tools for checking kidney function.
- eGFR (Creatinine-based)An estimate of how well your kidneys filter blood, worked out from your creatinine, age and sex.
- UreaUrea is the main waste product from breaking down protein. Your kidneys clear it from the blood.
- Uric AcidUric acid is a waste product from breaking down purines. High levels can lead to gout or kidney stones in some people.
- Urine Albumin/Creatinine Ratio (uACR)Compares albumin, a protein, with creatinine in a urine sample to show whether your kidneys are letting protein leak into urine.
Common follow-up tests
- Creatinine Clearance (24-Hour Urine)Compares creatinine in a 24-hour urine collection with creatinine in your blood to estimate how much blood your kidneys clear each minute.
- Cystatin CA small protein that nearly every cell makes and the kidneys clear from the blood, used to check kidney filtration without depending on muscle mass.
- eGFR (Creatinine + Cystatin C, CKD-EPI 2021)An estimate of how well your kidneys filter blood, worked out from both your creatinine and cystatin C levels plus your age and sex.
- eGFR (Cystatin C-based)An estimate of how well your kidneys filter blood, worked out from your cystatin C level, age and sex, without using creatinine.
- Urine Protein/Creatinine Ratio (UPCR)Compares the protein in a urine sample with its creatinine to estimate how much protein your kidneys are letting into your urine.
Calculators
- eGFR from creatinineFrom creatinine, age and sex
- eGFR from cystatin CFrom cystatin C, age and sex
- eGFR from creatinine and cystatin CFrom creatinine, cystatin C, age and sex
- Creatinine clearanceFrom urine creatinine, 24h urine volume and blood creatinine
- BUN to creatinine ratioFrom BUN and creatinine
- Urine albumin to creatinine ratioFrom urine albumin and urine creatinine
- Urine protein to creatinine ratioFrom urine total protein and urine creatinine