the menstrual cycle
Menstruation is a woman’s monthly bleeding, often called your period. When you menstruate, your body discards the monthly buildup of the lining of your uterus (womb). Menstrual blood and tissue flow from your uterus through the small opening in your cervix and pass out of your body through your vagina.
During the monthly menstrual cycle, the uterus lining builds up to prepare for pregnancy. If you do not get pregnant, estrogen and progesterone hormone levels begin falling. Very low levels of estrogen and progesterone tell your body to begin menstruation.
What is the menstrual cycle?
The menstrual cycle is the monthly hormonal cycle a female’s body goes through to prepare for pregnancy. Your menstrual cycle is counted from the first day of your period up to the first day of your next period. Your hormone levels (estrogen and progesterone) usually change throughout the menstrual cycle and can cause menstrual symptoms.
How long is a typical menstrual cycle?
The typical menstrual cycle is 28 days long, but each woman is different.2 Also, a woman’s menstrual cycle length might be different from month-to-month. Your periods are still “regular” if they usually come every 24 to 38 days.3 This means that the time from the first day of your last period up to the start of your next period is at least 24 days but not more than 38 days.
Some women’s periods are so regular that they can predict the day and time that their periods will start. Other women are regular but can only predict the start of their period within a few days.
What is ovulation?
Ovulation is when the ovary releases an egg so it can be fertilized by a sperm in order to make a baby. A woman is most likely to get pregnant if she has sex without birth control in the three days before and up to the day of ovulation (since the sperm are already in place and ready to fertilize the egg as soon as it is released). A man’s sperm can live for 3 to 5 days in a woman’s reproductive organs, but a woman’s egg lives for just 12 to 24 hours after ovulation.
Each woman’s cycle length may be different, and the time between ovulation and when the next period starts can be anywhere from one week (7 days) to more than 2 weeks (19 days).4
At different times in a woman’s life, ovulation may or may not happen:
- Women who are pregnant do not ovulate.
- Women who are breastfeeding may or may not ovulate. Women who are breastfeeding should talk to their doctor about birth control methods if they do not want to get pregnant.
- During perimenopause, the transition to menopause, you may not ovulate every month.
- After menopause you do not ovulate.
How do I know if I’m ovulating?
A few days before you ovulate, your vaginal mucus or discharge changes and becomes more slippery and clear. This type of mucus helps sperm move up into your uterus and into the fallopian tubes where it can fertilize an egg. Some women feel minor cramping on one side of their pelvic area when they ovulate. Some women have other signs of ovulation.
Luteinizing hormone (LH) is a hormone released by your brain that tells the ovary to release an egg (called ovulation). LH levels begin to surge upward about 36 hours before ovulation, so some women and their doctors test for LH levels. LH levels peak about 12 hours before ovulation.1 Women who are tracking ovulation to become pregnant will notice a slight rise in their basal temperature (your temperature after sleeping before you get out of bed) around ovulation. Learn more about tracking ovulation to become pregnant.
How does my menstrual cycle change as I get older?
Your cycles may change in different ways as you get older. Often, periods are heavier when you are younger (in your teens) and usually get lighter in your 20s and 30s. This is normal.
Talk to your doctor or nurse if you have menstrual cycles that are longer than 38 days or shorter than 24 days, or if you are worried about your menstrual cycle.
Why should I keep track of my menstrual cycle?
If your periods are regular, tracking them will help you know when you ovulate, when you are most likely to get pregnant, and when to expect your next period to start.
If your periods are not regular, tracking them can help you share any problems with your doctor or nurse.
If you have period pain or bleeding that causes you to miss school or work, tracking these period symptoms will help you and your doctor or nurse find treatments that work for you. Severe pain or bleeding that causes you to miss regular activities is not normal and can be treated.
How can I keep track of my menstrual cycle?
You can keep track of your menstrual cycle by marking the day you start your period on a calendar. After a few months, you can begin to see if your periods are regular or if your cycles are different each month.
You may want to track:
- Premenstrual syndrome (PMS) symptoms: Did you have cramping, headaches, moodiness, forgetfulness, bloating, or breast tenderness?
- When your bleeding begins: Was it earlier or later than expected?
- How heavy the bleeding was on your heaviest days: Was the bleeding heavier or lighter than usual? How many pads or tampons did you use?
- Period symptoms: Did you have pain or bleeding on any days that caused you to miss work or school?
- How many days your period lasted: Was your period shorter or longer than the month before?
You can also download apps (sometimes for free) for your phone to track your periods. Some include features to track your PMS symptoms, energy and activity levels, and more.
The average age for a girl in the United States to get her first period is 12.6 This does not mean that all girls start at the same age.
A girl may start her period anytime between 8 and 15. The first period normally starts about two years after breasts first start to develop and pubic hair begins to grow. The age at which a girl’s mother started her period can help predict when a girl may start her period.
A girl should see her doctor if:
- She starts her period before age 8.
- She has not had her first period by age 15.
- She has not had her first period within three years of breast growth.
How long does a woman usually have periods?
On average, women get a period for about 40 years of their life.6,7 Most women have regular periods until perimenopause, the time when your body begins the change to menopause. Perimenopause, or transition to menopause, may take a few years. During this time, your period may not come regularly. Menopause happens when you have not had a period for 12 months in a row. For most women, this happens between the ages of 45 and 55. The average age of menopause in the United States is 52.
Periods also stop during pregnancy and may not come back right away if you breastfeed.
But if you don’t have a period for 90 days (three months), and you are not pregnant or breastfeeding, talk to your doctor or nurse. Your doctor will check for pregnancy or a health problem that can cause periods to stop or become irregular.
What is a normal amount of bleeding during my period?
The average woman loses about two to three tablespoons of blood during her period.8 Your periods may be lighter or heavier than the average amount. What is normal for you may not be the same for someone else. Also, the flow may be lighter or heavier from month to month.
Your periods may also change as you get older. Some women have heavy bleeding during perimenopause, the transition to menopause. Symptoms of heavy menstrual bleeding may include:
- Bleeding through one or more pads or tampons every one to two hours
- Passing blood clots larger than the size of quarters
- Bleeding that often lasts longer than eight days
How often should I change my pad, tampon, menstrual cup, sponge, or period panties?
Follow the instructions that came with your period product. Try to change or rinse your feminine hygiene product before it becomes soaked through or full.
- Most women change their pads every few hours.
- A tampon should not be worn for more than 8 hours because of the risk of toxic shock syndrome (TSS)
- Menstrual cups and sponges may only need to be rinsed once or twice a day.
- Period panties (underwear with washable menstrual pads sewn in) can usually last about a day, depending on the style and your flow.
Use a product appropriate in size and absorbency for your menstrual bleeding. The amount of menstrual blood usually changes during a period. Some women use different products on different days of their period, depending on how heavy or light the bleeding is.
What is toxic shock syndrome?
Toxic shock syndrome (TSS) is a rare but sometimes deadly condition caused by bacteria that make toxins or poisons. In 1980, 63 women died from TSS. A certain brand of super absorbency tampons was said to be the cause. These tampons were taken off the market.
Today, most cases of TSS are not caused by using tampons. But, you could be at risk for TSS if you use more absorbent tampons than you need for your bleeding or if you do not change your tampon often enough (at least every four to eight hours). Menstrual cups, cervical caps, sponges, or diaphragms (anything inserted into your vagina) may also increase your risk for TSS if they are left in place for too long (usually 24 hours). Remove sponges within 30 hours and cervical caps within 48 hours.9
If you have any symptoms of TSS, take out the tampon, menstrual cup, sponge, or diaphragm, and call 911 or go to the hospital right away.
Symptoms of TSS include:10
- Sudden high fever
- Muscle aches
- Kidney or other organ failure
How does the menstrual cycle affect other health problems?
The changing hormone levels throughout the menstrual cycle can also affect other health problems:
- Depression and anxiety disorders. These conditions often overlap with premenstrual syndrome (PMS). Depression and anxiety symptoms are similar to PMS and may get worse before or during your period.
- Asthma. Your asthma symptoms may be worse during some parts of your cycle.11
- Irritable bowel syndrome (IBS). IBS causes cramping, bloating, and gas. Your IBS symptoms may get worse right before your period.
- Bladder pain syndrome. Women with bladder pain syndrome are more likely to have painful cramps during PMS.
For more information about the menstrual cycle check out the following resources from other organisations:
- Abnormal Uterine Bleeding – Information from the American College of Obstetricians and Gynaecologists.
- Menstruation and Menstrual Problems – Information from the Eunice Kennedy Shriver National Institute of Child Health and Human Development
- Toxic Shock Syndrome – Information from the Mayo Clinic
- Reed, B.G., Carr, B.R. (2015). The Normal Menstrual Cycle and the Control of Ovulation. Endotext [Internet]. South Dartmouth (MA): MDText.com, Inc.
- Chiazze, L., Brayer, F.T., Macisco, J.J., Parker, M.P., Duffy, B.J. (1968). The Length and Variability of the Human Menstrual Cycle. JAMA; 203(6): 377–380.
- Fraser, I.S., Critchley, H., Broder, M., Munro, M.G. (2011). The FIGO Recommendations on Terminologies and Definitions for Normal and Abnormal Uterine Bleeding. The Seminars in Reproductive Medicine; 29(5): 383-390.
- Wilcox, A. J., Dunson, D., Baird, D. D. (2000). The timing of the "fertile window" in the menstrual cycle: day specific estimates from a prospective study. British Medical Journal, 321(7271):1259-1262.
- American College of Obstetricians and Gynecologists. (2015). Menstruation in Girls and Adolescents: Using the Menstrual Cycle as a Vital Sign
- McDowell, M.A., Brody, D.J., Hughes, J.P. (2007). Has Age at Menarche Changed? Results from the National Health and Nutrition Examination Survey (NHANES) 1999–2004. Journal of Adolescent Health; 40(3): 227–231.
- Shifren, J.L., Gass, M.L.S., for the NAMS Recommendations for Clinical Care of Midlife Women Working Group. (2014). The North American Menopause Society Recommendations for Clinical Care of Midlife Women. Menopause; 21(10): 1038–1062.
- Centers for Disease Control and Prevention. (2015). Heavy Menstrual Bleeding.
- American College of Obstetricians and Gynecologists. (2016). Barrier Methods of Birth Control: Spermicide, Condom, Sponge, Diaphragm, and Cervical Cap.
- Matsuda, Y., Kato, H., Ono, E., Kikuchi, K., Muraoka, M., Takagi, K. (2008). Diagnosis of toxic shock syndrome by two different systems; clinical criteria and monitoring of TSST-1-reactive T cells. Microbiol Immunol; 52(11):513-21.
- Zein, J.G., Erzurum, S.C. (2015). Asthma is Different in Women. Current Allergy and Asthma Reports; 15(6): 28.
THE THREE MAIN PHASES OF THE MENSTRUAL CYCLE
The menstrual cycle is from Day 1 of bleeding to Day 1 of the next time of bleeding. The average cycle is 28-30 days. Girls usually start having menstrual periods between the ages of 11 and 14. Women usually start to have fewer periods from their late 30’s until menopause.
What controls the menstrual cycle?
Your hormones control your menstrual cycle. During each cycle, your brain's hypothalamus and pituitary gland send hormone signals back and forth with your ovaries. These signals get the ovaries and uterus ready for a pregnancy.
The hormones estrogen and progesterone play the biggest roles in how the uterus changes during each cycle.
- Estrogen builds up the lining of the uterus.
- Progesterone increases after an ovary releases an egg (ovulation) at the middle of the cycle. This helps the estrogen keep the lining thick and ready for a fertilized egg.
- A drop in estrogen causes the lining to break down. This is when your period starts.
Did you know that the menstrual cycle has three main phases?
- The menstrual phase
- The pre-ovulation phase
- The post-ovulation phase.
Phase 1, Menstrual (Days 1-5)
Begins from the start of your bleed until it ends and involves the shedding of the uterine wall lining. During this phase, the three main hormones; estrogen, progesterone & testosterone are at their lowest levels. Symptoms can include: Cramps, bloating, irritability, headaches, tiredness, tender breasts, lower back pain.
Phase 2, Pre Ovulation (Days 6-15)
Begins when the bleed has stopped. During this phase, the three main hormones; estrogen, progesterone & testosterone are all at peak levels. Symptoms can include ovulation cramping, headaches, heightened stress and or anxiety.
Phase 3, Post Ovulation (Days 16-30)
Begins after ovulation. During this phase, estrogen, testosterone and progesterone levels start to drop. Symptoms can include: PMS, mood swings, feeling sluggish and low energy.
Period cramps explained
Hormonal fluctuations at the start of menstruation trigger inflammatory compounds to build up in the uterus. These inflammatory compounds make uterine muscles tightly contract.
Lack of Oxygen = Cramps
Uterine muscles contract so powerfully, they can close off blood vessels that supply oxygen. This leads to period cramps.
Vitamins B1, B6, and B12 are key players in muscle contraction, nerve signaling, and hormonal regulation. Research shows they can help address a range of period symptoms and help restore important nutrition lost in menstrual blood.*
Zinc’s antioxidant and anti-inflammatory properties may help boost blood flow to the uterus, preventing the cut-off of oxygen to uterine muscles and the painful cramps that follow.*
Research suggests ginger inhibits the inflammatory compounds that cause period pain in the first place.*
Premenstrual syndrome (PMS)
What is PMS?
PMS is a combination of physical and emotional symptoms that many women get after ovulation and before the start of their menstrual period. Researchers think that PMS happens in the days after ovulation because estrogen and progesterone levels begin falling dramatically if you are not pregnant. PMS symptoms go away within a few days after a woman’s period starts as hormone levels begin rising again.
Some women get their periods with mild PMS. For others, PMS symptoms may be so severe that it makes it hard to do everyday activities like go to work or school. Severe PMS symptoms may be a sign of premenstrual dysphoric disorder (PMDD).
Who gets PMS?
As many as three in four women say they get PMS symptoms at some point in their lifetime.1
Does PMS change with age?
PMS symptoms may get worse as you reach your late 30s or 40s and approach menopause and are in the transition to menopause, called perimenopause.2
This is especially true for women whose moods are sensitive to changing hormone levels during the menstrual cycle. In the years leading up to menopause, your hormone levels also go up and down in an unpredictable way as your body slowly transitions to menopause. You may get the same mood changes, or they may get worse.
What are the symptoms of PMS?
PMS symptoms are different for every woman. You may get physical symptoms, such as bloating or gassiness, or emotional symptoms, such as sadness, or both. Your symptoms may also change throughout your life.
Physical symptoms of PMS can include:3
- Swollen or tender breasts
- Constipation or diarrhoea
- Bloating or a gassy feeling
- Headache or backache
- Lower tolerance for noise or light
Emotional or mental symptoms of PMS include:3
- Irritability or hostile behavior
- Feeling tired
- Sleep problems (sleeping too much or too little)
- Appetite changes or food cravings
- Trouble with concentration or memory
- Tension or anxiety
- Depression, feelings of sadness, or crying spells
- Mood swings
- Less interest in sex
What causes PMS?
Changes in hormone levels during the menstrual cycle may play a role.4 These changing hormone levels may affect some women more than others.
What can I do at home to relieve PMS?
These tips will help you be healthier in general, and may relieve some of your PMS symptoms.
- Get regular aerobic physical activity throughout the month.5 Exercise can help with symptoms such as depression, difficulty concentrating, and fatigue.6
- Choose healthy foods most of the time.7 Avoiding foods and drinks with caffeine, salt, and sugar in the two weeks before your period may lessen many PMS symptoms. Learn more about which foods are good to eat for each menstrual phase.
- Get enough sleep. Try to get about eight hours of sleep each night. Lack of sleep is linked to depression and anxiety and can make PMS symptoms such as moodiness worse.3
- Find healthy ways to cope with stress. Talk to your friends or write in a journal. Some women also find yoga,8 massage,9 or meditation10 helpful.
- Don’t smoke. In one large study, women who smoked reported more PMS symptoms and worse PMS symptoms than women who did not smoke.11
Should I take vitamins or mineral supplements for PMS symptoms?
Studies show that certain vitamins and minerals may help relieve some PMS symptoms.
Calcium may help correct PMS symptoms, like mood swings, backaches, and sore breasts. Large studies show that people who don’t get enough calcium have worse PMS moods. In clinical trials, calcium supplements reduced menstrual gloom and lifted energy levels.*
According to clinical studies, magnesium works in synergy with vitamin B6 to thwart mood changes. Research also shows that it can soothe headaches and reduce bloating on its own.*
Zinc levels are in flux throughout the menstrual cycle and tend to plummet just as PMS kicks in. Research shows those who supplement with zinc have more balanced moods during their periods.*
Chromium treatment was associated with reduced mood symptoms and improved overall health satisfaction in most participants.
Folic Acid supplementation was inversely associated with shorter (<27 days) menstrual cycle length. This association was strongest among women aged 18–30 years and women who used both Folic Acid and multivitamins.*
Some women report relief from their PMS symptoms with yoga or meditation. Others say supplements help relieve symptoms. Talk to your doctor before you take supplements and if your symptoms affect your daily life.
Formulated by experts, triumph monthly cycle supplement contains herbs and nutrients that target period symptoms at the source.
- Steiner, M. (2000). Premenstrual syndrome and premenstrual dysphoric disorder: guidelines for management. Journal of Psychiatry and Neuroscience; 25(5): 459–468.
- Pinkerton, J.V., Guico-Pabia, C.J., Taylor, H.S. (2010). Menstrual cycle-related exacerbation of disease. American Journal of Obstetrics and Gynecology; 202(3): 221-231.
- American College of Obstetricians and Gynecologists. (2015). Premenstrual Syndrome (PMS)
- Dickerson, L., Mazyck, P., Hunter, M. (2002). Premenstrual Syndrome. American Family Physician; 67(8): 1743–1752.
- El-Lithy, A., El-Mazny, A., Sabbour, A., El-Deeb, A. (2014). Effect of aerobic exercise on premenstrual symptoms, haemotological and hormonal parameters in young women. Journal of Obstetrics and Gynaecology; 3: 1–4.
- Aganoff, J. A., Boyle, G. J. (1994). Aerobic exercise, mood states and menstrual cycle symptoms. Journal of Psychosomatic Research; 38: 183–92.
- Kaur, G., Gonsalves, L., Thacker, H. L. (2004). Premenstrual dysphoric disorder: a review for the treating practitioner. Cleveland Clinic Journal of Medicine; 71: 303–5, 312–3, 317–8.
- Tsai, S.Y. (2016). Effect of Yoga Exercise on Premenstrual Symptoms among Female Employees in Taiwan. Int J Environ Res Public Health; 13(7).
- Hernandez-Reif, M., Martinez, A., Field, T., Quintero, O., Hart, S., Burman, I. (2000). Premenstrual symptoms are relieved by massage therapy. J Psychosom Obstet Gynaecol; 21(1):9-15.
- Arias, A. J., Steinberg, K., Banga, A., Trestman, R. L. (2006). Systematic review of the efficacy of meditation techniques as treatments for medical illness. Journal of Alternative and Complementary Medicine; 12(8):817-32.
- Dennerstein, L., Lehert, P., Heinemann, K. (2011). Global epidemiological study of variation of premenstrual symptoms with age and sociodemographic factors. Menopause International; 17(3): 96–101.
- Brownley KA, Girdler SS, Stout AL, McLeod MN. Chromium supplementation for menstrual cycle-related mood symptoms. J Diet Suppl. 2013 Dec;10(4):345-56.