The initial test on the urine is a screening chemical analysis for blood. A positive result for blood is simply a color change due to oxidation of a test-strip reagent but it does not confirm that red blood cells are present. Confirmation that there are red blood cells present in the urine is made by using a microscope to look for them. If the microscopic evaluation does not show a significant number of red blood cells, then the urine would NOT be positive for urinary blood. In sum, the diagnosis of microhematuria (blood in the urine not visible with the naked eye) should not be made from the results of only a dipstick result. Unless red blood cells are seen microscopically, the term hematuria or microhematuria is inappropriate. Many individuals with a positive “dipstick” blood test are labeled as having dipstick urinary blood cells although microscopic analysis would show that red blood cells are absent.