A high urine red blood cell count but negative urine occult blood may be due to vitamin C interference.
Urine occult blood generally have two kinds of dry chemical method and microscopic method, which urine red blood cell count belongs to microscopic method, urine occult blood belongs to dry chemical method.
Generally, the dry chemical method is more sensitive than the microscopic method, but it can be affected by vitamin C in the urine. If vitamin C in the urine is >100mg/L, it may interfere with the urinary occult blood test, resulting in negative results; however, if the urinary erythrocyte count is high, it usually indicates the presence of hematuria.
If the patient has a high urine erythrocyte count, it is recommended to go to a regular hospital in a timely manner, complete the examination to determine the cause of the disease, and then give targeted treatment or treatment under the guidance of the doctor.