Blood on paper after urination may be a normal physiological phenomenon, or it may be caused by certain diseases, such as urinary stones, trichomonas vaginitis, bladder cancer, etc., and you should consult a doctor in time to find out the cause of the disease. 1. Physiological factors: when a girl is in physiological period, she may discharge menstrual blood, and there will be blood when she wipes with paper after urination, which is a normal physiological phenomenon. 2. Pathologic factors: (1) urinary stones: due to the body’s metabolic abnormalities, infections, foreign bodies and medications lead to the formation of solid lumps in the urethra, patients may have hematuria, usually accompanied by pain, urination difficulties and other manifestations. (2) Trichomonas vaginitis: the pathogen is Trichomonas vaginalis, which mainly spreads directly through sexual behavior. Its main symptoms are increased vaginal secretion, vulvar itching, painful sexual intercourse, etc. When it is combined with urinary tract infection, hematuria can occur, accompanied by frequent urination and urgency. (3) Bladder cancer: patients with bladder cancer usually take painless and intermittent hematuria as the first symptom, which can be caused by capillary rupture and bleeding of epithelium of bladder tumor, with the appearance of washout. In addition, acute cystitis, bladder stones and other diseases can also appear after urination with paper with blood, bleeding people are recommended to timely consultation and treatment.