When urine is red at the beginning of urination, it is called initial hematuria, and it is usually caused by inflammation of the urethra. However, if there is inflammation in the urethra and the mucous membrane is oozing blood, the urine in the front part of the urine flushes the front urethra during the process of urination, which can cause the front part of the urine to have blood. As the urine in the anterior segment carries the blood out of the body, the urine in the posterior segment can appear clear and bright. This condition often indicates the presence of a urinary tract infection, which can have numerous causes and can be sexually transmitted diseases, such as gonorrhea and non-gonococcal urethritis. It may also be a non-specific urethritis, and a urine culture test is needed to confirm the diagnosis. It can also be caused by a tumor or stone in the urethra, but if there is a tumor or stone in the urethra, it can be accompanied by a feeling of obstruction in urination in addition to initial hematuria. In addition to the initial hematuria in the urinary tract, there may be a feeling of obstruction to urination, a feeling of difficulty or incompletion of urination, and a bifurcation of urination. If similar symptoms are present, urethroscopy is recommended to further rule out the presence of these lesions.