Many parents have this experience, checking the urine routine, the result is different every time, even the careful parents take the same urine of their children for two times, the result is different. And these times urine occult blood less, into 1 plus, after a few days again into 3 plus, always fluctuating up and down, this is why? 1, urine occult blood test itself is a screening program, more sensitive, easy to have some errors. 2, urine occult blood is affected by more factors, such as urine contains more vitamin C, it can appear false negative, or make urine occult blood performance is relatively light; urine if it contains myoglobin or bacteria, it can appear false positive, or make urine occult blood performance is relatively heavy. 3, urinary occult blood is also affected by the dilution and concentration of urine, generally speaking, the first urine in the morning is more concentrated, urinary occult blood is heavier, the urine at other times or drink water for a period of time after the discharge of urine is more dilute, urinary occult blood may be lighter. 4, Exercise, infection, allergies and many other factors can increase urinary occult blood for a short period of time. In view of some drawbacks of urine occult blood test, we all recommend to dynamically monitor the number of red blood cells in the urine sediment to determine the changes in the child’s hematuria. You can also insist on testing in the same hospital laboratory, each time with morning urine or random urine, and then write down the addition of the urinary occult blood count and compare it dynamically over a longer period of time, such as 1 to 2 months, to see if the hematuria decreases or worsens.