A Brief Guide To The Menstrual Cycle
Getting to know your menstrual cycle is key to getting to know yourself. Learn what your cycle is and how it works to build your self-knowledge.
If you received menstrual cycle education beyond how to use a tampon when you were growing up, consider yourself one of the lucky few. For many women and menstruators, we never had access to information about what's happening during our menstrual cycles, muchless why they’re so important. In this guide, we’ll explain the very basics of the menstrual cycle, from what it is to how it works, because it’s never too late to learn.
What is the Menstrual Cycle?
The menstrual cycle is the process your body goes through to prepare for a potential pregnancy. It involves the development and release of an egg, the building of the uterine lining–the endometrium–and its shedding in the event no pregnancy occurs, and all the hormone level fluctuations that make these physiological changes possible.
Contrary to popular belief, a healthy menstrual cycle can last anywhere from 26-34 days, and only a small percentage of menstruators actually experience a 28-day cycle. Cycle length can change over the course of your lifetime. But in general, a healthy cycle will be fairly consistent in length from month to month. And while we’re mythbusting, let’s be clear that ovulation does not always happen on cycle day 14.
A Sign of Health
Regardless of where you stand on having kids or how many times you’ve heard that you don’t really need a period, your menstrual cycle is a key sign of your overall health. Plus, the hormones at play in your menstrual cycle are important for long-term health, especially as you age.
Your menstrual cycle occurs within the complex, interconnected system of your body. This means that what’s happening in the rest of your body–like chronic stress, illness or insufficient nutrition–can affect your menstrual cycle. And vice versa: your menstrual cycle affects your entire body, not just what’s happening in your reproductive organs. So if you’ve been wondering why your preferences, strengths or needs seem to change over the course of the month, understanding your menstrual cycle can explain a lot.
More Than A period
If there’s one aspect of our cycles we are most familiar with collectively, it is the menstrual phase, simply because it’s the most visible. The menstrual phase is our bleed. It’s what we are referring to when we say we’re “on our period”. But your bleed is actually just one phase of your menstrual cycle, which also includes the follicular, ovulatory and luteal phases.
Looking at your cycle as a whole–rather than just at the bleed–is essential to your well-being.
Observing changes throughout your cycle can help you to both identify patterns of concern and observe if any lifestyle changes or interventions are successfully changing these patterns.
Getting to know yourself during each phase of your cycle is also a key way to bring more ease–and hopefully even pleasure–into your monthly rhythm. As you get to know your patterns, you’ll be able to anticipate your shifts and plan ahead, so that you can flow with your cycle rather than against it.
A Cycle in Four Phases
Now let’s dive into what happens during each of the phases and the roles of the key hormones that direct the process.
Follicular (7-10 days) - In this estrogen dominant phase of your cycle, your body is preparing for ovulation, the release of an egg. Following your bleed, Follicle Stimulating Hormone (FSH) continues to stimulate follicles in your ovaries, in partnership with Luteinizing Hormone (LH), which will ultimately help the most dominant follicle reach maturity. At the same time, estrogen–specifically Estradiol, which is produced in your ovaries–is at work rebuilding your uterine lining and operating in a feedback loop with FSH and LH to coordinate the impending ovulation.
Ovulatory (3-4 days) - This phase starts when a surge of LH causes the mature follicle to release an egg. The egg is then swept into the fallopian tubes, where it can be fertilized by sperm as it is carried toward the uterus. If no sperm are present to fertilize the egg, it will disintegrate within 24 hours. But because of conditions that support sperm longevity prior to the big moment of egg release, your fertile window includes the days leading up to ovulation.
Luteal (10-14 days) - The burst follicle forms the corpus luteum on the ovary and begins producing progesterone, the dominant hormone in the second half of your cycle. The functions of progesterone include preventing the release of additional eggs in the current cycle and signaling to the body to enrich and retain the uterine lining in case of possible pregnancy.
If no fertilization has taken place, the corpus luteum is reabsorbed into the body and ceases progesterone production, approximately 10-16 days after ovulation.
Menstrual (3-7 days) - This sharp decline in progesterone–followed by a decline in estrogen–at the end of the luteal phase cues the body to shed the uterine lining it has built up during this cycle, which initiates menstrual bleeding. The hormones involved in your cycle are at their lowest levels during the beginning of this phase with FSH the first to rise, making this phase both the end and the beginning of your cycle. Cycle day 1 is largely recognized as the first day of your bleed.
Now that you know how your menstrual cycle works, help other women and menstruators learn too. Please share this resource, so we can build our body literacy together.
Photo Credit: Larisa Birta
Disclaimer: This article is intended for educational and entertainment purposes only. None of the information provided should be construed as medical advice. If you have concerns related to your menstrual cycle, please consult a licensed health care provider.