The period or menstruation is a normal biological process that occurs about once a month, in which blood and tissue are shed and expelled from the uterus through the vagina, as a natural part of a woman’s menstrual cycle. While it is an experience shared by almost all women of reproductive age —roughly over two billion people—it is still a widely stigmatized topic.1
The Significance of Menstruation
Feelings of shame and vulnerability surround the topic of menstruation. Many women, especially young teens, are not comfortable talking about it. It largely stems from the universal understanding that menstruation is a private issue. Something to be kept hidden. Tampons have been introduced in the 1920s or early 1930s, but it was not until 1985 that the word “period” was first heard on American television.2
It didn’t help that, in every culture in history, a variety of strange myths and misconceptions has been attributed to menstruation. Ancient history had taught that menstruating women were unclean and toxic to those around them. That they would sour wine, make crops wither, blunt knives, or make dogs rabid.3 Unfortunately, misinformation about menstruation still persists in today’s age.
A lot of girls will grow up without any knowledge about their own menstrual cycles, what is considered normal and what is not. Menstrual taboos are dangerous for women. Your period is essential for your well-being and lack of awareness can compromise your health and fertility.
Why Women Menstruate
A woman’s first period, also known as menarche, comes between ages 8 to 15. The average age is 12.4 The onset of menstruation signals maturation of the adolescent female body. This implies that a woman is able to ovulate and reproduce. However, this does not guarantee ovulation or fertility, nor does it signify that a woman is ready to get pregnant.
If the ovulated egg is not fertilized, the lining of the uterus and blood are shed and your period starts. It is your body’s way of removing tissue that is no longer needed. After your period, the process begins all over again.
The “Normal” Period
The textbook description of a normal menstrual cycle is about 28 days long with a period lasting three to five days.5 But many healthy women do not have this menstrual pattern.6 The menstrual cycle interval also varies among age groups.7
Clinical guidelines state that menstrual cycles can range from 21 to 388 days for adult women and 21 to 45 days9 for adolescent girls. The variation in cycles is due mainly to the timing of ovulation and hormone levels. The characteristics of a woman’s cycle may also be affected by weight gain, stress, and lifestyle factors.10
To determine your menstrual cycle, count the days starting from the first day of your last period to the first day of your next period. It should be at least 24 days and not more than 38 days. It’s normal for your cycle to slightly differ from month to month. You may find it easier to track your menstrual cycle using period tracking apps.
What Happens During Your Period
As mentioned above, your cycle depends on the time of ovulation and your body’s hormone levels. These factors are interdependent because failure to ovulate (anovulation) will affect hormone levels, particularly estrogen and progesterone, and hormonal imbalance may alter the sequence of events that initiate ovulation.
The Role of Hormones
The endocrine glands that are responsible for the production of hormones and regulation of your menstrual cycle are the hypothalamus, the pituitary, and the ovaries. Collectively, they are known as the female reproductive axis or hypothalamic-pituitary-ovarian unit. They work together using a mechanism called the feedback loop.11
Each month the lining of the uterus called the endometrium prepares for pregnancy or the implantation of an embryo. During the follicular phase of the menstrual cycle, the developing ovarian follicles produce more and more estrogen, which stimulates the growth of the endometrium.
Estrogen continues to increase as one of the ovarian follicles mature to become an egg. The increasing levels of estrogen will trigger the release of gonadotropin-releasing hormone (GnRH) from the hypothalamus, which will then signals the release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) from the pituitary.
The surge of LH and FSH triggers the release of the egg or ovum and ovulation starts. FSH levels drop immediately and LH declines gradually. The next stage after ovulation is called the luteal phase.
The Shedding of the Endometrium
The mature follicle where the egg develops turns into a corpus luteum. If there is no pregnancy, the corpus luteum disintegrates and the endometrium starts to shed.
The shedding of endometrium and the consequent bleeding is followed by an increase in uterine contractions, similar to that at the onset of labor. These contractions are more commonly known as cramps. The uterus continues to contract for three to five days until the endometrial remains and blood have been expelled.
Sometimes menstrual blood is expelled by retrograde flow through the fallopian tubes into the spaces of the pelvic cavity. The blood loss in this manner is reabsorbed through the tissues that line the abdominal wall and the organs in the abdomen.
While this can be beneficial in preserving iron, this retrograde flow can also cause serious problems such as infection and endometriosis.12
What to Watch Out For
Several factors about your period are worth monitoring to be aware of possible reproductive or hormonal problems:
- Irregularities in the menstrual cycle
- The length of the cycle
- The length of menstruation
- The amount of pain
- The volume and flow of blood
- Other physical and psychological symptoms
A variety of medical conditions can cause abnormal uterine bleeding. These include endometrial disorders, fibroids and polyps, polycystic ovary syndrome, and cancer. Talk to your gynecologist if you are experiencing heavy bleeding, severe or prolonged cramps, or irregular periods.
- Unicef. FAST FACTS: Nine things you didn’t know about menstruation. www.unicef.org. https://www.unicef.org/press-releases/fast-facts-nine-things-you-didnt-know-about-menstruation. Published May 25, 2018. Accessed September 26, 2020.
- The History of Tampax | Tampax®. Tampax.com. https://tampax.com/en-us/about/our-story/history-of-tampax/. Published 2020. Accessed September 26, 2020.
- Trickey R, Trickey Enterprises. Women, Hormones & the Menstrual Cycle. Fairfield, Vic.: Melbourne Holistic Health Group; 2011.
- Lacroix AE, Langaker MD. Physiology, Menarche. Nih.gov. https://www.ncbi.nlm.nih.gov/books/NBK470216/. Published April 25, 2019.
- Mihm M, Gangooly S, Muttukrishna S. The normal menstrual cycle in women. Animal Reproduction Science. 2011;124(3):229–236. doi:10.1016/j.anireprosci.2010.08.030
- Fehring RJ, Schneider M, Raviele K. Variability in the Phases of the Menstrual Cycle. Journal of Obstetric, Gynecologic & Neonatal Nursing. 2006;35(3):376-384. doi:10.1111/j.1552-6909.2006.00051.x
- Treloar AE, Boynton RE, Behn BG, Brown BW. The Menstrual Cycle. Obstetrical & Gynecological Survey. 1968;23(1):81-84. doi:10.1097/00006254-196801000-00011
- World Health Organization multicenter study on menstrual and ovulatory patterns in adolescent girls. II. Longitudinal study of menstrual patterns in the early postmenarcheal period, duration of bleeding episodes and menstrual cycles. World Health Organization Task Force on Adolescent Reproductive Health. Journal of Adolescent Health Care: Official Publication of the Society for Adolescent Medicine. 1986;7(4):236–244. http://www.ncbi.nlm.nih.gov/pubmed/3721946. Accessed September 28, 2020.