A 4-year-old girl with 3+ leukocytes on urine test may have nephritis, or it may be caused by urethritis, cystitis, etc., or it may be caused by not paying attention to hygiene. Normal urine test leukocytes should be negative, if the urine test leukocytes show 3 +, suggesting that there may be urinary tract infections, such as nephritis, cystitis, urethritis, etc., such as accompanied by frequent urination, painful urination and other symptoms, you need to go to the hospital to improve the relevant examination to identify the cause of the disease. Can also be caused by contact with contaminated clothing and bedding, public baths, etc., need to detach from the source of pollution, usually pay attention to hygiene. So, 4-year-old girl urine test leukocytes 3 + is not necessarily nephritis, in addition to the above reasons there are other reasons, if the child accompanied by frequent urination, urinary pain and other symptoms, or urine test continues to be positive for leukocytes, parents need to take the child to the hospital pediatrics in time to avoid delaying the condition.