Urinalysis red blood cells greater than 3 / high power field of view or (+) should be taken seriously, but can not be based solely on the number of red blood cells in the urine test to determine the severity of the disease. Normal urine should not have red blood cells, urine test in the high power field of view in the presence of more than 3 red blood cells can be diagnosed microscopic hematuria, the naked eye can be seen in the urine color red, equivalent to 1 ml of blood per liter of urine, can be diagnosed with microscopic hematuria. Hematuria is usually caused by urinary stones, urinary tract infection or trauma, urinary tumors, glomerular lesions, and certain medications. In conclusion, hematuria should be further investigated, if it is infection or stone, it can be cured after treatment; if it is tumor or renal lesion, it should be started as soon as possible; if it is caused by medication, it should be communicated with the relevant doctor whether to stop or change the medication.