The possible causes of a drop or two of blood at the end of urination are: 1. Infection of the posterior urethra or infection of the bladder neck, which can cause hematuria at the end of urination, accompanied by pain in the posterior urethra at the end of urination, as well as symptoms related to urinary frequency and urgency. 2. Bladder stones or stones in the posterior urethra, which can cause hematuria at the end of urination, accompanied by pain in the posterior urethra at the end of urination, as well as symptoms related to urinary frequency and urgency, suggesting urethroscopy and urinary routine examination to further confirm the presence of infection. The presence of polyps or tumors in the urethra may lead to local bleeding during urination, with the pressure of urethral closure pushing blood out of the urethral orifice, and may be accompanied by a feeling of difficulty in urination or abnormal urination. If there is any polyp or tumor in the urethra, urethroscopy should be performed to rule out the presence of such diseases as polyps or tumors.