Why Do We Get Our Period?

Getting your period is a natural part of growing up. This article explains the process and all the changes that your body goes through to prepare for it.

Table of Contents

What is a period?

A period is a process in which a female bleeds through their vagina. It is a part of the menstrual cycle. The first period is called menarche. A female gets their first period between the ages of 8 and 15. This is when they hit puberty.


The period is a part of the menstrual cycle. The menstrual cycle is a process that indicates reproductive maturity. It usually comes with other changes in the body, like acne, weight gain, body hair, and the development of breasts.

Diagram of the female reproductive system
Diagram of the female reproductive system Credit: Wikimedia/Cancer Research UK

The menstrual cycle

The menstrual cycle, on average, lasts 28 days. During this cycle, the egg, also known as the ovum, undergoes changes before it is finally released into the uterus. In the uterus, it awaits a sperm. If a sperm and the egg meet, they fuse to form a zygote. The zygote forms a baby. But it is not necessary for the menstrual cycle to end in pregnancy. If the egg is not fertilized, it disintegrates and is shed along with the menstrual blood. This process has 3 phases.


Menstrual phase: This is the actual bleeding phase. It lasts for 5–7 days. It marks day 1 of the menstrual cycle. This happens only if the female is not pregnant. The blood contains the egg, the cells of the uterus, and vaginal fluid.


Proliferative phase: The proliferative phase starts on day 8 of the menstrual cycle. This stage prepares the body for a possible pregnancy by making the tissues of the uterus thicker. Ovulation is the release of the egg from the ovary. It takes place on day 14 of this phase.


Secretory phase: This phase takes place from day 14 to day 28 of the menstrual cycle. During this time, large amounts of the hormone progesterone are released by the remnants of the unfertilised egg.


The lining of the uterus undergoes phases of thinning and thickening to prepare for pregnancy. During pregnancy, menstruation completely stops. Around the age of 50, a female reaches menopause. They no longer menstruate.

The events of the menstrual cycle
The events of the menstrual cycle Credit: Wikimedia/CFCF

How long does a period last?

The average menstrual cycle is around 28 days. The bleeding phase lasts for about 5–7 days. The bleeding is the heaviest during the first two days. Period blood is normally dark red in color and becomes lighter towards the end. On average, a menstruating female loses 30–72ml (5–12 teaspoons) of blood.


Some females have a condition called polycystic ovarian syndrome (PCOS). In PCOS, fluid-filled sacs called cysts are formed in the ovary. These cysts prevent the timely release of eggs, causing irregular periods. There are many causes of PCOS, including the build-up of hormones called androgens. The exact cause of PCOS is not yet known, but it can be managed with exercise, healthy eating, and maintaining healthy body weight.


PCOS is not the only reason for missed or irregular periods. Changes to the diet, infections, travel, and stress can also cause a female to miss their period.

An ovary with cysts
An ovary with cysts Credit: Wikimedia/http://www.scientificanimations.com

What happens to your body during your period?

Apart from bleeding, menstruators may also face mild to severe stomach cramps, back and body pain, bloating, sore breasts, food cravings, mood swings, and fatigue. Mood swings are caused by the various hormones released to maintain the period.


Premenstrual syndrome (PMS) is a group of symptoms that occur before the period. During PMS, females experience body soreness, intense emotions, and tiredness. Sometimes, PMS takes on a severe form known as premenstrual dysphoric disorder (PMDD). PMDD interferes with normal life by causing emotional instability.

Self-care during your period

There are many products that are used during the period. These can be pads, tampons, menstrual cups, or period underwear. Pads are stuck to the underwear and they absorb the blood. Pads should be changed every 4–8 hours to prevent infections.

Sanitary pads come in various sizes depending on the flow
Sanitary pads come in various sizes depending on the flow Credit: Wikimedia/Pastorius

Tampons also absorb blood. They are inserted into the vagina. Tampons also need to be changed every 4–8 hours, since they can cause toxic shock syndrome (TSS). TSS is caused by bacteria. It can cause damage to the kidney, heart, and liver. In severe cases, it can lead to death. Symptoms of TSS include dizziness, a sudden fever spike, vomiting, and diarrhea.

A tampon has a string that is used to remove it
A tampon has a string that is used to remove it,Credit: Wikimedia/Kaldari

Pads and tampons are single-use, and contribute heavily to pollution. That is why many menstruators prefer more sustainable options, like reusable cloth pads, menstrual cups, and period underwear.


Your period need not be stressful. There are ways to make it easier to get through. A little self-care can go a long way. Some of the best methods to have a comfortable period include sleeping well, doing light exercise, staying hydrated, and eating healthy foods full of fiber. Heating pads, warm showers, and over-the-counter painkillers help with cramps.


The period seems like a scary time, but it does not need to be. It may be uncomfortable, but there are many ways to make it easier to deal with. It is just a natural and common process. Open discussions about periods and the menstrual cycle make it less overwhelming. Period talk extends not only to menstruators, but also people that do not menstruate. It is essential to end the stigma around menstruation.


Androgen: A male hormone that develops and maintains masculine characteristics


Dysphoric: Very unhappy, uneasy, or dissatisfied


Progesterone: The hormone that regulates the cycle and prepares the uterus for pregnancy. In the absence of pregnancy, progesterone levels drop and the bleeding phase begins.


Puberty: The physical change in which a child’s body becomes an adult’s body capable of sexual reproduction


Zygote: The fertilised egg cell that results from the fusion of the ovum and sperm

Flesch Kincaid Grade Level: 7.1


Flesch Kincaid Reading Ease: 64.3

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  • Sanjana Kadur
    : Author
    Sanjana is doing her masters in biochemistry. She loves all things biology and truly believes that dogs make the world a better place. She enjoys playing basketball and spends most of her evenings on the court. Writing for Smore Science gives her the creative freedom to write about science in a fun and relatable way.

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