Not only cause blood in urine in girls, but also painful urination for the following reasons: 1. Consider the presence of acute urinary tract infections, such as acute cystitis, pyelonephritis can appear painful urination, meatus hematuria, and also frequent urination, urinary urgency, chills, high fever, lower abdomen or waist soreness, pain and discomfort. 2. The discharge of stones in the bladder through the urethra will cause urethral tingling, followed by fresh blood to the urethral orifice. After the infection is controlled, further color ultrasound or CT examination of the urinary system and cystoscopy if necessary should be done to find out whether there is urinary tumor, tuberculosis, stones, adenoidal cystitis and other diseases complicating the urinary tract infection.