Compares urea and creatinine to give quick context on kidney health and hydration.
The urea to creatinine ratio is a calculated value, not a separate blood test. It compares urea (blood urea nitrogen) with creatinine, two waste products the kidneys filter out of the blood.
The formula is: urea ÷ creatinine, using the units reported by the lab. In countries that report BUN, a related BUN to creatinine ratio is used.
Urea and creatinine are both cleared by the kidneys but behave differently. Urea is influenced by hydration, protein intake and bleeding in the gut, while creatinine tracks more closely with kidney filtration. Their ratio helps locate where a problem with kidney function may lie.
A high ratio can point toward dehydration or reduced blood flow to the kidneys, sometimes called a pre-renal pattern, or to gastrointestinal bleeding. A low ratio can suggest low protein intake, liver disease or overhydration. It is read as supporting context.
Aniva reads your result against research-backed ranges, not just the lab's wide normal. The reference shown below is specific to this biomarker.
Reference patterns depend on whether urea or BUN is reported and on the units, so use the reporting lab's guidance. As a general clue, a high ratio suggests a pre-renal or dehydration pattern, while a low ratio suggests low protein intake or liver involvement. Interpret with a clinician alongside the actual values.
Urea rises with high protein intake, dehydration, gastrointestinal bleeding and corticosteroids, and falls with low protein intake and liver disease. Creatinine depends on muscle mass. These independent influences mean the ratio must always be read with the individual values and the clinical picture.
Read with its components, urea and creatinine, and alongside estimated GFR, electrolytes and hydration status.
What do my results mean? A higher ratio often points to dehydration or more urea production; a lower ratio may reflect low protein intake or reduced urea production. Your clinician will interpret it with other tests.
Do I need to fast? No. Fasting is not required for this test.
What can affect the ratio? Hydration, high-protein diet, creatine supplements, recent hard exercise, pregnancy, and some medicines can shift results.
How often should I test it? It’s usually checked when kidney results change or during follow-up. Your clinician will advise the timing.
How long do results take? Results are usually ready in about 7 days.
What should I discuss with my clinician? Share your medications, supplements, hydration, recent illness, and whether you need eGFR or a urinalysis for context.
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