Menstrual cycle

1. What are hormones?

Hormones are chemicals that are produced in the body. They control and regulate the activity of certain cells and organs. They are involved in all types of things, like emotions, growth, digestion, metabolism, and reproduction. Hormones are seen as messengers: controlling and coordinating activities throughout the body. Hormones are very powerful, so a little too much or not enough of a certain hormone can be a serious problem.

Hormones are produced in endocrine glands. The produced hormones are directly passed from the endocrine gland cells to the blood flowing through the gland. In the human body, hormones can be used for communication between two endocrine glands or for communication between an endocrine gland and an organ.

2. What is a menstrual cycle?

A menstrual cycle consists of all the changes the female body goes through in preparation for pregnancy. All mammals have some sort of menstrual cycle, but human females are the only species that have a cycle every month.

There are two types of menstruation: covert menstruation and overt menstruation. Covert menstruation is the breakdown of the uterus lining without vaginal discharge, while overt menstruation is the menstruation as we know it from human females. However, overt menstruation happens to close relatives such as chimpanzees as well. Why humans and close relatives are the only species that have a menstrual cycle is mostly unknown.

Other mammals, such as dogs and cats, undergo oestrous cycles. This is like a menstrual cycle, but slightly different, with the main difference being menstruation. They experience covert menstruation; their body reabsorbs the uterus lining if they don’t get pregnant. The only period they’re sexually active is when they’re “in heat”: a period of time in which the female is ready to have sex and is able to get pregnant, also known as being ‘in estrus’.

This essay will be about menstrual cycles in human females. To understand how this menstrual cycle works, it’s also important to know what the female reproduction system (see picture) consists of. The uterus, also known as the womb, is an organ located in the middle of the lower abdomen where a fertilized egg grows into a baby. The ovaries are located at the two sides of the uterus and the organ where eggs are produced. They’re connected to the Fallopian tubes: those carry fertilized eggs from the ovaries to the uterus. At the lower part of the uterus, there is a narrowing. This is called the cervix: the cervix allows menstrual blood to go from the uterus into the vagina and directs sperm into the uterus during intercourse. The vagina, located under the cervix, is a canal used for childbirth, intercourse and as a passageway for menstrual blood.

Each month, one of the ovaries of the female body develops an egg and the uterus lining starts to thicken. Then, ovulation occurs; the ovary releases the egg. If the egg isn’t fertilized during the ovulation, the egg is reabsorbed into the body and the uterus lining sheds through the vagina. While the uterus lining is disposed, tiny blood vessels in the uterus lining break, which leads to blood loss. This is called menstruation or a period: the discharge of blood and uterus lining through the vagina.

3. How does a menstrual cycle work?

The menstrual cycle is regulated by hormones, and how they rise and fall in a specific pattern. The pattern consists of four stages, as mentioned below. One menstrual cycle is usually 28* days.

3.1 Menstrual phase.

The first stage is the stage in which the period occurs, and it lasts 3-7* days. The symptoms of the menstrual phase are listed in chapter 3.1. The menstrual stage starts when an egg from the previous cycle isn’t fertilized. Because the egg isn’t fertilized and pregnancy doesn’t occur, the estrogen and progesterone levels drop.

3.2 Follicular phase.

The follicular phase and the menstrual phase overlap; the follicular phase begins on day 1 of the period and ends when ovulation. In the start, the hypothalamus (a part of the brain that regulates the release of hormones, among other things) will release follicle-stimulating hormone, also known as FSH. This stimulates the ovaries to produce around 5 to 20 small sacs, called follicles, which contain an immature egg. The healthiest egg will eventually mature, while the rest will be reabsorbed. The maturing follicles will set out a rush of estrogen, which thickens the uterus lining. The follicular phase lasts 16* days.

3.3 Ovulation phase.

Because of the rising estrogen levels in the follicular phase, the pituitary gland (a gland in the brain that produces and releases hormones) releases luteinizing hormone, also known as LH. This makes the process of ovulation start; the ovary releases a mature egg. The egg travels towards the uterus through the Fallopian tubes, ready to be fertilized. The ovulation phase is the only phase in which pregnancy can occur, but because sperm can live for up to 5 days, pregnancy can occur when having intercourse 5 days prior to the ovulation. The ovulation itself usually lasts a day.

3.4 Luteal phase.

After the follicle releases the egg, it changes into the corpus luteum: a structure that releases progesterone and a bit of estrogen. These hormones keep the uterus lining thick, in case that a fertilized egg will implant. When that happens, the body produces human chorionic gonadotropin (hCG), which maintains the corpus luteum and the thickness of the uterus lining. This is the hormone pregnancy tests detect.

If you’re not pregnant, the corpus luteum will be reabsorbed, causing a drop in estrogen and progesterone levels. This causes the beginning of your period. During this phase, you can experience PMS symptoms, which will be discussed in chapter 3.1. The luteal phase lasts 14* days.

*In an average cycle; every women’s cycle is different and can change over time.

4. Women’s experiences during menstruation

Females usually begin to menstruate when they start puberty. This can be anywhere from 8 years old to 15 years old. In the first two years, periods can be irregular; this means that the cycle is longer than 35 days, or that it varies in length. Women menstruate from their first period until their menopause: these are the years in which a woman slowly stops menstruating and can’t get pregnant naturally anymore. The menopause usually begins when a woman is around 45 to 55 years old.

4.1 Symptoms

Periods usually last 3 to 7 days and apart from bleeding, they come with a variety of other symptoms. Because every woman’s period is different, not all women have the following symptoms.

Breasts swelling and tenderness.
Feeling bloated.
Leg, back and stomach cramping.
Headaches.
Acne breakouts.
Bowel issues.
Trouble sleeping.
Feeling tired.
Mood swings.
Food cravings.

Women can also get these symptoms, along with some other symptoms, before their period. This is called PMS (Premenstrual syndrome): physical and emotional symptoms that start one to two weeks someone’s period and stop around the start of bleeding. It affects around 95 percent of women with periods.

4.2 Menstrual products: now and in the past

Menstrual products, also known as female hygiene products, are products used during menstruation to catch menstrual blood and tissue. The most used types of menstrual products are:

Sanitary napkins/menstrual pad: a narrow piece of material that is stuck into the underwear. It can have “wings” that fold over the sides of the underwear, to avoid leaking. Some pads are made of disposable materials; made to use once and then be thrown away. But some pads are made from fabric and can be washed and reused.
Tampons: a little plug that fits inside of the vagina. Tampons have a string attached to the end to pull them out. Some tampons come with an applicator to make the insertion easier. Most tampons are disposable, but tampons made from fabric do exist.

Ninety-eight percent of American women uses disposable pads or disposable tampons, though pads appear to be used most often. What does the other two percent use, besides tampons and pads made from fabric? This are four less known types of menstrual products:

Menstrual cup: a reusable, silicone cup that seals against the vaginal wall, just below the cervix. Menstrual cups have a stem attached to remove them. They collect the menstrual flow rather than absorbing it. They are less used because insertion can be difficult.
Menstrual disc: similar to a menstrual cup, but they are disc-shaped with a flexible outer ring and a soft, fold-able center. They can be messy to remove, but the main advantage is that intercourse is possible while wearing the disc. Menstrual discs can be disposable or reusable.
Period underwear: reusable underwear designed to replace other menstrual products or to be worn with menstrual products for extra protection. Variations of this product are period bathing suits and period leggings.
Menstrual sponge: a reusable or disposable sea sponge that fits inside of the vagina. However, it’s not recommended by most gynecologists, mainly because it isn’t possible to totally sterilize a sponge. It doesn’t have a lot of advantages besides being made from all-natural ingredients and allowing intercourse while being worn.

How a (from left to right) tampon, menstrual cup and menstrual disc fit in the body.

4.3 How birth control affects menstruation

Birth control, also known as contraception and fertility control, is a method or device used to prevent pregnancy. Hormonal birth control can affect your menstrual cycle and your periods, such as:

Birth control pills: a kind of medicine with hormones that needs to be taken every day. The pills can either contain the hormones estrogen and progestin (combination pills) or only the hormone progestin (mini pills).
Birth control implants: a tiny, thin rod with hormones that is inserted under the skin of the upper arm by a doctor and can be worn for 5 years. The implant slowly releases a progestin hormone into the body.
Birth control shots: a hormone injection injected by a doctor that works for three months; after that, a new shot is needed. The hormone in this shot is the progestin hormone as well.
Hormonal IUD’s: a tiny, T-shaped device that’s put into the uterus through the cervix by a doctor. They last 3 to 10 years. An IUD contains the progestin hormone.
Birth control vaginal rings: a small, flexible, plastic ring that is inserted into the vagina by the woman itself. It continuously releases the estrogen and progestin hormone.
Birth control patches: a small, square patch that is stuck to the skin by the woman itself every week. It continuously releases the estrogen and progestin hormone.

But how does this affect the menstrual cycle? The hormones progestin and estrogen in the birth control fully stop ovulation from occurring. So, the ovaries don’t release eggs anymore and there is no egg to be fertilized. They also thicken the mucus on the cervix because this blocks sperm from entering the uterus.

Progestin-only birth control methods work a little bit differently. Besides thickening the mucus on the cervix, it also thins the lining of your uterus where the fertilized egg would implant. This makes it harder for the egg to implant and prevents a pregnancy from growing. Progestin-only birth control might stop ovulation; for example, about 40% of women who take progestin-only pills continue to ovulate.

5. Should menstrual products be free?

Recently, Scotland was on the news because the country is set to become the first in the world to offer period products free to women. However, the new bill, introduced by Monica Lennon, still needs to go through two more stages before it’s passed. The goal is to end period poverty: the inability of women to afford and easily find menstrual products.

Even though many people agreed that it would be a wonderful idea, some were less positive. This are some of the used reasons from people that were positive about the idea:

If menstrual products are expensive or not easily accessible in public places, women will wear the same menstrual product for longer than supposed to, leading to medical difficulties. As well as using a dangerous alternative, such as tampons out of toilet paper.
Menstrual products are a right, not a luxury: women can’t choose if they have their period or not. It’s especially unfair that menstrual products are taxed as a luxury in some countries or states.

This were some of the used reasons from people who didn’t think it was a good idea:

If the government makes something ‘free’, we’ll need to pay for it through taxes. I don’t want to have to take on the responsibility for paying for anyone’s menstrual products but my own.
If periods are a natural bodily function that we must live with, and we feel like menstrual products should be free because they are necessary to hygiene and health, doesn’t that mean we shouldn’t have to pay for toilet paper and other things? A counter argument: in public bathrooms, toilet paper, water, soap and hand towels are always free. Menstrual products cost money or are simply not available.
Tampons and pads aren’t that expensive: we should worry about more important things the government should fund, like college tuition and healthcare.

I personally think that public restrooms should have tampons and pads, in case you forgot your own menstrual products or got your period unexpectedly. I don’t think women would abuse getting free tampons: you don’t see people stealing toilet paper or soap from restrooms often either. This will also make menstrual products accessible for homeless women. However, I think menstrual products in shops shouldn’t be free, just like toilet paper and most medicine isn’t, but it shouldn’t be taxed as a luxury.

6. Sources

Written in March 2020.