Menstruation is the monthly cycle experienced by a woman's body. Every month, one of the ovaries releases an egg through the process of ovulation. At the same time, hormonal changes occur in a woman's body to prepare the uterus for possible pregnancy. If ovulation takes place but the egg is not fertilized by sperm, the lining of the uterus which contains blood and tissue will decay and be expelled through the vagina. This process is known as menstruation.

Hormones Affecting Phases in the Menstrual Cycle

In principle, the menstrual cycle consists of several phases which are controlled by five types of hormones in the body, namely:

1. Estrogen

This hormone is produced by the ovaries and has a major role in the ovulation process. In addition, estrogen also plays a role in body changes during puberty and is involved in rebuilding the lining of the uterus after menstruation.

2. Progesterone

Working with estrogen, the hormone progesterone plays a role in maintaining the reproductive cycle and supporting pregnancy. The ovaries also produce this hormone which helps the lining of the uterus to thicken.

3. Follicle Stimulating Hormone (FSH)

This hormone functions to stimulate the development of egg cells in the ovaries until they are ready to be released. FSH is produced in the pituitary gland which is at the base of the brain.

4. Luteinizing Hormone (LH)

Like FSH, the hormone LH is also produced by the pituitary gland and helps stimulate the ovaries to release eggs.

5. Gonadotropin-Releasing Hormone (GnRH)

GnRH is produced by the brain and has an important role in stimulating the body to produce FSH and LH hormones. These two hormones influence the maturation and release of the egg.

Understanding the Menstrual Process

Generally, the menstrual cycle will go through the following four phases:

1. Menstrual Phase

If during the menstrual phase there is no fertilization between the egg and sperm, the inner lining of the uterus which consists of blood vessels, uterine cells, and mucus will slough off and be expelled through the vagina. The menstrual phase begins on the first day of the menstrual cycle and lasts 4-7 days. In this phase, women will usually experience abdominal and lower back pain due to uterine contractions to expel the lining of the uterus.

2. Follicular Phase

The follicular phase lasts from the start of menstruation until just before ovulation. During this phase, the ovaries or ovaries will produce follicles which contain eggs. As the ovarian follicles develop, the inner lining of the uterus that was previously sloughed off will thicken again to "prepare" the ideal environment for an egg to be fertilized by a sperm.

3. Ovulation Phase

The ovulation phase is also known as the female fertile period. In this phase, the mature follicle will release an egg for possible fertilization. The mature egg cell will move through the fallopian tube to the uterus. This egg cell can only survive for 24 hours. If there is no fertilization by sperm, the egg will die. Meanwhile, if fertilization occurs, the fertilized egg will develop into a fetus. Generally, the ovulation phase occurs about 2 weeks before the next menstrual cycle begins.

4. Luteal Phase

After ovulation, the ruptured follicle transforms into a structure known as the corpus luteum. The corpus luteum stimulates the production of the hormone progesterone to strengthen the lining of the uterus. The luteal phase is also known as the premenstrual phase. During this period, many women experience various symptoms such as breast tenderness, acne breakouts, physical tiredness, and feeling irritable or emotional. The duration of the luteal phase varies from 11-17 days, with the average woman experiencing it for 14 days. The menstrual cycle will continue to repeat until a woman enters menopause. Usually, menopause occurs at the age of 40 and over.

It is important to remember that every woman has a unique menstrual cycle. What is considered normal for you may not be the same for someone else. Therefore, it is important to know and understand your own menstrual cycle, such as when menstruation usually comes and how long periods last.

References:

https://www.alodokter.com/yang-terjadi-selama-siklus-menstruasi

https://www.halodoc.com/artikel/ini-proses-menstruasi-yang-terjadi-pada-wanita-setiap-bulan

https://www.alodokter.com/seperti-ini-proses-menstruasi-pada-wanita-setiap-bulan