Urine occult blood positive first of all to exclude false positive results: 1, whether female? Is it during the regular holidays? If yes, the urine specimen is contaminated, and then recheck after the holiday. 2, recently whether the cold, the human body will appear when the cold in the urine occult blood positive, do not worry, after the cold will naturally disappear. 3, the specimen pollutants caused by false positives, such as peroxidase-like substances contamination can cause false positives. Such contamination can be boiled urine for 10 minutes, cooled and then rechecked. False positive urine test for occult blood in about 30%. Specimen contaminants false positive exclusion method: you can boil the urine for 10 minutes, cool and recheck, if it is a contaminant will become negative. When re-retaining urine for rechecking, you can ask the examiner to perform a microscopic examination, and if the microscopic examination is positive, you should find the relevant experts to analyze the source of blood and urine.