Why does period happen?

Menstruation, or a period, is the shedding of the lining of the uterus (womb). It occurs when a fertilized egg does not implant in the uterus, causing the levels of the hormones estrogen and progesterone to drop. This drop in hormones signals the uterus to shed its lining, which is then expelled through the vagina.

Here is a more detailed explanation of the process:

1. The menstrual cycle begins with the menstrual phase, which is when the lining of the uterus (the endometrium) is shed through the vagina. This phase typically lasts for 3-7 days.

2. The follicular phase then begins, during which an egg develops in one of the ovaries. This phase typically lasts for 10-14 days.

3. When the egg is mature, it is released from the ovary in a process called ovulation. This usually occurs around day 14 of the menstrual cycle.

4. If the egg is not fertilized, it will die and the levels of estrogen and progesterone will drop. This drop in hormones signals the uterus to shed its lining, which is then expelled through the vagina.

5. This process repeats itself each month until a woman becomes pregnant.

The length of a menstrual cycle can vary from woman to woman, but it typically lasts for 28 days. Some women may have periods that are shorter or longer than this, however.

Menstruation is a normal part of a woman's reproductive life.