Menstrual Disorders Normal Menstruation Body Changes During the Menstrual Cycle By Tracee Cornforth Tracee Cornforth LinkedIn Tracee Cornforth is a freelance writer who covers menstruation, menstrual disorders, and other women's health issues. Learn about our editorial process Updated on January 22, 2023 Medically reviewed by Anita Sadaty, MD Medically reviewed by Anita Sadaty, MD Facebook LinkedIn Twitter Anita Sadaty, MD, is board-certified in obstetrics-gynecology. She is a clinical assistant professor at Hofstra Northwell School of Medicine and founder of Redefining Health Medical. Learn about our Medical Expert Board Print Up to two weeks before a menstrual period, hormone-driven changes in the body trigger a collection of premenstrual symptoms (PMS). These changes can cause cramps, breast pain, fatigue, mood swings, and upset stomach. Individual symptoms may vary since everyone's menstrual cycle is unique. Other body changes during the menstrual cycle are less obvious. The menstrual cycle is controlled by several hormones, including estrogen and progesterone, which are produced by follicles in the ovaries. Hormone shifts throughout the month may affect your mood and energy levels. This article explains what happens to your body on your period. It breaks down the four phases of the menstrual cycle, explaining how key events that occur during each phase of the menstrual cycle may affect you. ericsphotography / Getty Images What Happens to Your Body on Your Period? Your period is just one part of the menstrual cycle. The menstrual cycle consists of four distinct phases: Menstrual phaseFollicular phaseOvulationLuteal phase Here's what changes happen in the body during each phase of the menstrual cycle: Menstrual Phase The first phase of the menstrual cycle is the menstrual phase, also known as your period. The menstrual phase starts on day one when you get your period, and ends when your period stops, usually around days five to seven. During this phase, the lining of the uterus, the endometrium, thickens in preparation for pregnancy. If pregnancy does not occur, the endometrium needs to "reset" by shedding its excess lining. Leading up to a period, increased levels of the hormone progesterone widen milk ducts in the breasts and prepare the uterus for pregnancy. When implantation doesn't occur, progesterone levels quickly withdraw, triggering the endometrium to shed and the period to begin. According to the International Federation of Gynecology and Obstetrics, menstruation should last no longer than eight days. If yours lasts longer or you do not have a period at all, consult with your healthcare provider. While on your period, you may feel one or more of the following symptoms: Abdominal or pelvic crampsLower back painBloatingSore breastsFood cravingsMood swings and irritabilityHeadacheFatigue 7 Period Facts Everyone Should Know Follicular Phase The second phase of the menstrual cycle is the follicular phase. This phase overlaps with your menstrual phase, beginning on day one with your period and ending when you ovulate, around day 14. An ovarian follicle is a small, fluid-filled sac in the ovary that contains an egg. The ovaries contain about 400,000 follicles by the time puberty begins. During the start of the follicular phase, the anterior pituitary gland triggers rising levels of follicular stimulating hormone (FSH). FSH causes several ovarian follicles to undergo maturation. Between days 10 to 14 of the menstrual cycle, just one ovarian follicle will fully mature into an egg. It's also during this phase that progesterone decreases and estrogen peaks, causing the endometrium to thicken in preparation for ovulation. Decreased progesterone levels may have a positive effect on you. Research shows that lower progesterone levels are linked to greater strength, power, and energy in athletes during the follicular phase of their cycles. The most fertile period of a normal menstrual cycle is the last three days of the follicular phase leading up to ovulation. You may hear this referred to as the "fertile window." How to Get Pregnant: Tips to Increase Your Fertility Ovulation The third phase of the menstrual cycle is ovulation, occurring around day 14 of a 28-day cycle. During this time, luteinizing hormone (LH) levels suddenly surge, triggering ovulation within about 24 to 48 hours. Estrogen levels decrease during the LH surge while progesterone begins to rise again. Ovulation occurs when the dominant ovarian follicle, containing a fully-matured egg, bursts, releasing the egg into the fallopian tube where it can be fertilized by a sperm. Sperm is viable for approximately three days, but the released egg is only viable for one—the day of ovulation. Therefore, conception is most likely to occur if you have intercourse in the three days leading up to ovulation. Cervical mucus is a common symptom of ovulation. You may notice it in your underwear or when you use the restroom. The discharge is typically clear, stretchy, and slippery like a raw egg white. If you are trying to get pregnant, the best time to have intercourse is when you notice cervical mucus as it means you are ovulating. Luteal Phase The fourth stage, called the premenstrual or luteal phase, occurs around day 15 of the menstrual cycle. It lasts about 14 days and ends when you get your period. During the luteal phase, the follicle that released an egg in ovulation changes into a structure called the corpus luteum. This structure produces progesterone and estrogen. The rising hormone levels help thicken the endometrium. If the egg is not fertilized with sperm, the corpus luteum dissolves, hormone levels decline, and the endometrium gets ready to shed. A period then marks the end of the luteal phase and the start of a new menstrual cycle. According to an article published by the Harvard Review of Psychiatry, anxiety, stress, and binge eating may occur more frequently during the luteal phase. The External and Internal Female Reproductive Organs Hormones and Your Menstrual Cycle The menstrual cycle starts with your endocrine glands because they produce the hormones that determine when you get your period, the amount of menstrual flow, and what happens to your reproductive organs. The area of the brain called the hypothalamus connects your nervous and endocrine system by way of the pituitary gland, which also is in the brain, and controls the hormones necessary for reproductive health and your period. Six hormones serve as chemical messengers to your reproductive system: Gonadotropin-releasing hormone (GnRH) Follicle-stimulating hormone (FSH) Luteinizing hormone (LH) Estrogen Progesterone Testosterone During your menstrual cycle, the hypothalamus first releases GnRH. This causes a chemical reaction in the pituitary gland and stimulates the production of FSH and LH. Your ovaries produce estrogen, progesterone, and testosterone (yes, the "male" hormone) in reaction to stimulation by FSH and LH. When these hormones work harmoniously, normal menstrual cycles occur. Hormones and Your Menstrual Cycle Summary The average menstrual cycle is 28 days long. Each menstrual cycle is comprised of four distinct phases: the menstrual and follicular phases, ovulation, and the luteal phase. Shifts in estrogen, progesterone, and other reproductive hormones can cause various symptoms throughout the month. Premenstrual symptoms like cramps and fatigue as well as clear discharge during ovulation are common. You may also notice changes in your mood and energy levels, particularly during the follicular and luteal phases. A Word From Verywell It is normal to have some uncomfortable symptoms at various times in your menstrual cycle, but only to a certain degree. If you are doubled over in pain or your symptoms are interfering with your life, considering seeing your healthcare provider or a gynecologist to rule out the possibility of another underlying cause. Some conditions like endometriosis can cause severe pain that isn't normal and must be treated. How Endometriosis Is Treated 13 Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Pokharel P, Rana J, Moutchia J, et al. Effect of exercise on symptoms of premenstrual syndrome in low and middle-income countries: a protocol for systematic review and meta-analysis. BMJ Open. 2020 Sep;10(1):e039274. doi:10.1136/bmjopen-2020-039274 Barbieri R. The endocrinology of the menstrual cycle. Methods Mol Biol. 2014;1(1154):145-169. doi:10.1007/978-1-4939-0659-8_7 National Cancer Institute. Mammary glands. Edelman A, Boniface E, Benhar E, et al. Association between menstrual cycle length and coronavirus disease 2019 (COVID-19) vaccination. Obstet Gynecol. 139(4):481-489. doi:10.1097/AOG.0000000000004695 Eunice Kennedy Shriver National Institute of Child Health and Human Development. What are the symptoms of menstruation?. National Cancer Institute. Ovaries. Paludo A, Paravlic A, Dvořáková K, Gimunová M. The effect of menstrual cycle on perceptual responses in athletes: A systematic review with meta-analysis. Front Psychol. 2022 Jul;13(1):10.3389/fpsyg.2022.926854 Carmichael M, Thomson R, Moran L, Wycherley T. The impact of menstrual cycle phase on athlete's performance: A narrative review. Int J Environ Res Public Health. 2021 Feb;18(4):1667. doi:10.3390/ijerph18041667 UCSF Center for Reproductive Health. Normal menstrual cycle. Intermountain Healthcare. Ovulation made simple: A four phase review. Owen M. Physiological signs of ovulation and fertility readily observable by women. Linacre Q. 2013 Feb;80(1):17-23. doi:10.1179/0024363912Z.0000000005 Bull J, Rowland S, Scherwitzl E, Scherwitzl R, Danielsson K, Harper J. Real-world menstrual cycle characteristics of more than 600,000 menstrual cycles. NPJ Digital Med. 2019 Aug;2(1):1-8. doi:10.1038/s41746-019-0152-7 Handy A, Greenfield S, Yonkers K, Payne L. Psychiatric symptoms across the menstrual cycle in adult women: A comprehensive review. HRP. 2022;30(2):100-117. doi:10.1097/HRP.0000000000000329 Additional Reading Cleveland Clinic. Normal menstruation. By Tracee Cornforth Tracee Cornforth is a freelance writer who covers menstruation, menstrual disorders, and other women's health issues. See Our Editorial Process Meet Our Medical Expert Board Share Feedback Was this page helpful? Thanks for your feedback! What is your feedback? Other Helpful Report an Error Submit