Kidney Guides
Creatinine, BUN, urine protein, and kidney function testing.
Kidney guides focus on the markers used to assess how well the kidneys filter blood and remove waste. Common tests include creatinine, which is used to estimate filtration rate (eGFR), blood urea nitrogen (BUN), and urine tests for protein such as albumin.
Kidney markers are usually interpreted together and in the context of hydration, medications, blood pressure, and diabetes, all of which can affect results. A single value rarely tells the whole story, which is why panels are common.
Because the kidneys help regulate fluid and electrolytes, results can shift with dehydration, intense exercise, or a high-protein meal, so consistency in how and when you test helps.
Persistent changes over more than one test are usually more meaningful than a single out-of-range value, and they are what a provider typically follows over time. Some medications and supplements can affect kidney markers, so it helps to say what you take.
Urine and blood tests are often combined to give a fuller picture of kidney health than either test alone. Results are generally returned within a few business days, and reference ranges vary by laboratory.
Each guide explains what a marker measures and how results are typically reported. This content is educational and is not medical advice; review your kidney function with a qualified healthcare provider.