Therefore, creatinine levels in blood and urine may be used to calculate the creatinine clearance (CrCl), which correlates with the glomerular filtration rate (GFR).

(In the absence of secretion, creatinine behaves like inulin.

In both categories, the deterioration in kidney function is quantified either by an elevation in creatinine level in the blood, or by decreased clearance of creatinine in the urine.

The trend of serum creatinine levels over time is more important than absolute creatinine level.

Using both ACEI and ARB concomitantly will increase creatinine levels to a greater degree than either of the two drugs would individually.

eGFR can be accurately calculated using serum creatinine concentration and some or all of the following variables sex, age, weight, and race, as suggested by the American Diabetes Association without a 24 hour urine collection.

The typical human reference ranges for serum creatinine are 0.5 to 1.0 mg dl (about 45 90 μmol l) for women and 0.7 to 1.2 mg dl (60 110 μmol l) for men.

Creatinine levels may be normal in the early stages of CKD, and the condition is discovered if urinalysis (testing of a urine sample) shows the kidney is allowing the loss of protein or red blood cells into the urine.

In the absence of hematemesis, an upper source for GI bleeding is likely in the presence of at least two factors among black stool, age 50 years, and blood urea nitrogen creatinine ratio 30 or more.