Menstruation is the gradual thickening of the uterine lining by the cyclical changes in the level of sex hormones in the body. When the thickening reaches a certain level, under the influence of progesterone, blood vessel hyperplasia occurs, the glands grow and secrete as well as the shedding of the uterine lining causing bleeding. Menstrual blood is generally composed of blood and the shedding of the uterine lining, under normal circumstances will not appear in the menstrual white transparent things, if a small amount of white transparent mucus-like things, may be the cervical secretion along with the menstrual blood outflow. If you have a history of menopause, coupled with the presence of white transparent material in the bleeding, you should check whether the situation is caused by pregnancy and miscarriage.