In the event that an egg is not fertilised, it has a viability of about a single day. The ovary's monthly release of an egg prompts the uterus to thicken its lining, ensuring it is suitable for nourishing a fertilised egg. However, in the absence of fertilisation, this thickened lining is rendered unnecessary and thus begins the process of menstruation. This menstrual cycle involves the slow breakdown and shedding of the uterine lining, which exits the body as blood and mucous through the vagina. Typically, menstruation occurs every month and lasts from two to eight days, serving as a critical indicator of female reproductive health. Understanding this cycle is important as it connects hormonal changes, reproductive capabilities, and overall health in females.