A small amount of mucus filaments can be found in normal urine. When mucus filaments are high in routine urine tests, it is considered to be caused by kidney and ureteral diseases, which may include pyelonephritis, tubular lesions, and decreased filtration function of the kidneys, resulting in elevated mucus filaments. When ureteral infection occurs bacteria will stimulate the ureteral epithelial cells, causing them to secrete large amounts of mucus filaments. Female patients need to be aware that the vagina and urethra are closer together and vaginal secretions may flow into the urine when urine specimens are retained, and vaginal secretions also contain mucus filaments, which can cause elevated mucus filaments in urine. Certain urological tumors such as prostate cancer, bladder cancer, ureteral epithelial cancer, cancer cells will also decompose mucus filaments in urine, and the number of mucus filaments will increase sharply, which should be taken seriously.