MIL: During the time of period, the blood which is getting discharged is unclean, so she is not supposed to touch any vessels. P1: Everyone are saying we should stay away. Dr: Come on!! Everyday for both men and women wastes goes out of body in the form of urine and stool. Even that is unclean right?? if it comes in the form of blood its unclean so we should stay away from them. If it comes in the form of human waste that ok. What is this!! hahhaha. Shanthi: correct doctor. But on what basis are you saying that periods blood is not unclean? Dr: Good, I will give details answer for this question. Every girl will have ovaries in her body which consists of small eggs which helps to give birth to child. This has been joined with fallopian tube to their uterus. As the girls grow even these parts will also grow. Once these gets matured, every month an egg comes out and through fallopian tube it enters uterus. To save these eggs, this forms blood linings. MIL: What is lining Dr.? Dr: Honey bees forms a groups. In the same way it is also same. This is called as uterine lining. Uterus forms this. In science it is called as endometrium. P1: What is the relationship between and this and monthly periods? Dr: Thats what I am saying. Monthly egg gets formed and from that day to till 14 days uterus forms this endometrium. If the egg meets with sperm successfully, pregnancy takes place. If not this will come out in the form of blood for 3 to 7 days. This is called as periods, menstruation. So this is not unclean blood.