The test strip method is now commonly used for routine urine tests, including the urine occult blood test. It is the use of red blood cells in the hemoglobin and reagents on the test paper chemical reaction, the release of ionized oxygen, resulting in the oxidation of the chromogenic agent to determine the results. This method of testing positive urine occult blood that is hematuria is very one-sided, for the following reasons: 1, if there is a strong oxidizing agent in the urine, both can directly make the color developer oxidation color. At this time, although there is no hemoglobin in the urine, the experimental results are also positive. 2, when there are a large number of bacteria in the urine, some bacteria can also cause a chemical reaction similar to hemoglobin, the experimental result is also positive. 3, due to the test to detect hemoglobin is too sensitive, in the high-powered field of view of the urine red blood cells only 1-3, did not reach the standard of hematuria, the chromogenic agent may also present color. 4, urine occult blood test detection of hemoglobin, some factors lead to intravascular hemolysis of hemoglobinuria, although not hematuria, the results are also positive. Therefore, positive urine occult blood test is not necessarily hematuria, should be done centrifugal urine sediment microscopic high-powered field examination, only the latter can confirm the diagnosis of hematuria.