Menstruation, or period, is normal vaginal bleeding that occurs as part of a woman's monthly cycle. Every month, your body prepares for pregnancy. If no pregnancy occurs, the uterus, or womb, sheds its lining. The menstrual blood is partly blood and partly tissue from inside the uterus. It passes out of the body through the vagina.

Periods usually start between age 11 and 14 and continue until menopause at about age 51. They usually last from three to five days. Besides bleeding from the vagina, you may have

• Abdominal or pelvic cramping pain
• Lower back pain
• Bloating and sore breasts
• Food cravings
• Mood swings and irritability
• Headache and fatigue

Premenstrual syndrome, or PMS, is a group of symptoms that start before the period. It can include emotional and physical symptoms.

Consult your health care provider if you have big changes in your cycle. They may be signs of other problems that should be treated.

What is menstruation?

Menstruation (pronounced men-stroo-EY-shuhn) is normal discharge of blood and tissue from the uterine lining through the vagina (see diagram) that occurs as part of a woman's monthly menstrual cycle. Menstruation occurs between menarche (pronounced muh-NAHR-kee), a girl's first period, and menopause, when menstrual cycles end. The average menstruation time in normally menstruating women is about 5 days. In the United States, most girls start menstruating shortly after 12 years of age.

What is the menstrual cycle?

The menstrual cycle is the monthly process in which female hormones stimulate an ovary to release an egg, thicken the lining of the uterus to support a pregnancy, and then cause the uterus to shed this lining (through menstruation) if there is no pregnancy. The average menstrual cycle is 28 days, but this varies between women and from month to month. In teens, the menstrual cycle can range from 21 to 45 days, but for most women, it is 21 to 35 days.

Day 1

The first day of bleeding is considered the first day of the menstrual cycle. After bleeding ends, usually around day 5, levels of the hormone estrogen begin to rise. The rise in estrogen causes the lining of the uterus to thicken as it prepares to hold a fertilized egg. At the same time, the changes in hormone levels cause follicles (the sacs in the ovary that contain eggs) to grow and mature, in preparation for one follicle to go through ovulation.

Ovulation

Around day 12 to 14 in an average 28-day cycle, the egg is released from a follicle on the ovary in a process called ovulation (pronounced ov-yu-LAY-shuhn). Ovulation can occur anywhere between 10 and 21 days after the first day of a woman's menstrual cycle. A woman can tell when she has begun ovulating using several methods, including at-home tests that measure levels of luteinizing hormone (LH) in the urine and keeping track of her body temperature, which typically rises slightly at ovulation. At mid-cycle, some women experience pain on one side of their pelvic area; this pain is called "Mittelschmerz" (meaning "middle pain," because it occurs in the middle of the cycle) and may be a signal of ovulation.

If a pregnancy does not occur, decreasing hormone levels signal for the lining of the uterus, called the endometrium, to be shed during menstruation.

The endometrium builds up and breaks down during the menstrual cycle. The endometrium is thickest halfway through the 28-day cycle. Then, if there is no pregnancy, it breaks down. This breakdown causes the bleeding of the menstrual phase. This diagram illustrates an average 28-day cycle.

What happens if a pregnancy occurs?

Fertilization

After ovulation, the egg moves down the fallopian tube. The sperm can fertilize the egg at this point. After the sperm is ejaculated into the vagina, it moves into the cervix and through the uterus into the fallopian tube. Sperm can live up to 5 days in a woman's body.
If fertilization occurs, the newly formed embryo travels through the fallopian tube into the uterus, where it implants in the wall of the uterus. If fertilization does not occur, the egg naturally breaks down, and the uterine wall is lost in the form of menstrual bleeding.

Implantation

The embryo must successfully implant into the thickened wall of the uterus for the pregnancy to occur. The embryo first attaches to the wall of the uterus around 5 or 6 days after ovulation. It becomes more firmly implanted between 6 and 12 days after ovulation. Implantation causes a release of hCG—a hormone that signals the body to change to support the pregnancy. This hormone is what a pregnancy test detects.

The primary sign of menstruation is bleeding from the vagina. Additional symptoms include:

• Abdominal or pelvic cramping
• Lower back pain
• Bloating and sore breasts
• Food cravings
• Mood swings and irritability
• Headache
• Fatigue

Menses - Shedding of the inner portion of the endometrium out though the vagina; also referred to as menstruation.

The Menstrual Cycle

We can put everything together to talk about the three phases of the menstrual cycle—the series of changes in which the uterine lining is shed, rebuilds, and prepares for implantation.

The timing of the menstrual cycle starts with the first day of menses, referred to as day one of a woman’s period. Cycle length is determined by counting the days between the onset of bleeding in two subsequent cycles. Because the average length of a woman’s menstrual cycle is 28 days, this is the time period used to identify the timing of events in the cycle. However, the length of the menstrual cycle varies among women, and even in the same woman from one cycle to the next, typically from 21 to 32 days.

Just as the hormones produced by the granulosa and theca cells of the ovary “drive” the follicular and luteal phases of the ovarian cycle, they also control the three distinct phases of the menstrual cycle. These are the menses phase, the proliferative phase, and the secretory phase.

Menses Phase

The menses phase of the menstrual cycle is the phase during which the lining is shed; that is, the days that the woman menstruates. Although it averages approximately five days, the menses phase can last from 2 to 7 days, or longer. As shown in Figure, the menses phase occurs during the early days of the follicular phase of the ovarian cycle, when progesterone, FSH, and LH levels are low. Recall that progesterone concentrations decline as a result of the degradation of the corpus luteum, marking the end of the luteal phase. This decline in progesterone triggers the shedding of the stratum functionalis of the endometrium.

Proliferative Phase

Once menstrual flow ceases, the endometrium begins to proliferate again, marking the beginning of the proliferative phase of the menstrual cycle (see Figure). It occurs when the granulosa and theca cells of the tertiary follicles begin to produce increased amounts of estrogen. These rising estrogen concentrations stimulate the endometrial lining to rebuild.

Recall that the high estrogen concentrations will eventually lead to a decrease in FSH as a result of negative feedback, resulting in atresia of all but one of the developing tertiary follicles. The switch to positive feedback—which occurs with the elevated estrogen production from the dominant follicle—then stimulates the LH surge that will trigger ovulation. In a typical 28-day menstrual cycle, ovulation occurs on day 14. Ovulation marks the end of the proliferative phase as well as the end of the follicular phase.

Secretory Phase

In addition to prompting the LH surge, high estrogen levels increase the uterine tube contractions that facilitate the pick-up and transfer of the ovulated oocyte. High estrogen levels also slightly decrease the acidity of the vagina, making it more hospitable to sperm. In the ovary, the luteinization of the granulosa cells of the collapsed follicle forms the progesterone-producing corpus luteum, marking the beginning of the luteal phase of the ovarian cycle. In the uterus, progesterone from the corpus luteum begins the secretory phase of the menstrual cycle, in which the endometrial lining prepares for implantation (see Figure). Over the next 10 to 12 days, the endometrial glands secrete a fluid rich in glycogen. If fertilization has occurred, this fluid will nourish the ball of cells now developing from the zygote. At the same time, the spiral arteries develop to provide blood to the thickened stratum functionalis.

If no pregnancy occurs within approximately 10 to 12 days, the corpus luteum will degrade into the corpus albicans. Levels of both estrogen and progesterone will fall, and the endometrium will grow thinner. Prostaglandins will be secreted that cause constriction of the spiral arteries, reducing oxygen supply. The endometrial tissue will die, resulting in menses—or the first day of the next cycle.

Day 1 Your period begins and the flow is at its heaviest. You may have cramps, stomach pain, or lower back pain.

Day 2 Your period still likely is heavy, and you may have cramps or stomach pain.

Days 3/4 Your body removes the rest of the tissue in the uterus (womb). This sometimes can come out as dark clumps.

Days 5/6/7 There is still some blood, but the cramps should be over.

Days 8/9 The bleeding and pain usually are over.

Days 10/11/12 Your body should feel great! Even though you don’t have your period, changes are still happening in your reproductive system.

Days 13/14 Ovulation happens around this time. (Some women have cramps, but you likely won’t feel a thing when you ovulate.)

Days 15/16 Hormone levels rise. At the same time, your breasts may be tender.

Days 17/18/19/20 Your hormones are shifting, which can cause any or all of these symptoms:

• Bloating
• Tender or sore breasts
• Moodiness
• Cramping

You may feel very emotional during this phase, but many young women do not have pain or mood changes at all.

Days 21/22 A drop in hormone levels can cause you to feel tired, and you may feel like you need more time alone. You may start to get pimples around this time.

Days 23/24 If you have PMS (premenstrual syndrome), you may have any or all of the following symptoms:

• Mood swings
• Worries about things that may not be important
• Lack of interest in usual activities
• Tiredness
• Breast pain
• Bloating
• Headaches
• Food cravings
• Trouble focusing

Days 25/26 Important hormones are at very low levels, so you may have even stronger PMS symptoms. Symptoms may include:

• Mood swings
• Worries about things that may not be important
• Lack of interest in usual activities
• Tiredness
• Breast pain
• Bloating
• Headaches
• Food cravings
• Trouble focusing

Days 27/28 This is the end of the menstrual cycle, and your hormone levels have gone way down. The lining of your womb gets ready to be shed during this time, and your body prepares to start the cycle again. Many women have cramps during this time, which can let you know that your period is about to begin.

Getting your period is a fact of life for most women. But every woman’s period is different. So how do you know if yours is causing problems that it shouldn’t?

Many girls and women get cramps, low back pain, fatigue, or discomfort with their periods. But some have pain so bad they miss days of work or school every month. Others experience such heavy bleeding that it exhausts them.

These are things that may signal a bigger issue. But some women find talking about menstrual issues embarrassing.

“Women tend not to talk about pelvic pain or bleeding,” says Dr. Lisa Halvorson, a women’s health expert at NIH. “But the menstrual cycle is a critical part of your health.”

You can’t know about your treatment options unless you talk with your doctor.

Common Issues

Most women’s menstrual cycles range between 21 to 35 days, or up to 45 days for teens. Bleeding usually lasts between three to seven days. It’s important for women to get to know their own pattern. What’s normal for one woman may not be for another.

The most common menstrual irregularities are not getting your period at all or not getting it regularly, getting it for too many or too few days, or having severely painful cramps.

These issues can be caused by many different things, including scarring, hormonal imbalances, certain diseases or conditions, and even some medications.

Two of the most common disorders that cause period problems are uterine fibroids and endometriosis.

Fibroids are tumors, or growths, made of muscle cells and other types of cells that grow inside or outside of the wall of the uterus, or womb.

Studies estimate that more than 70% of women in the U.S. have at least one fibroid during their lives. But most women who have them don’t have symptoms.

Endometriosis is caused by tissue normally found in the uterus growing outside it on other organs. Many women with endometriosis never have any symptoms. But some have life-altering ones.

“Endometriosis probably accounts for at least a third of infertility in women,” Halvorson explains.

Fibroids, endometriosis, and other menstrual issues can cause a range of symptoms (see the Wise Choices box). Your doctor can help you figure out what’s causing the symptoms.

Very heavy bleeding during a woman’s period is the most common symptom of fibroids. Severe pain that gets worse around the time of a woman’s period is the most common symptom of endometriosis.

Both fibroids and endometriosis can run in families, explains Dr. Ayman Al-Hendy, an NIH-funded gynecologist at the University of Illinois. Because of this, women may not know that severe pain or heavy bleeding aren’t normal.

“The culture in a family could be, ‘you just have to put up with it, it’s part of being a woman,’” he explains. “But there are treatments available that can improve your health and your quality of life.”

Finding the Cause

It can be hard for doctors to tell menstrual problems apart. Blood tests can help detect hormonal changes. An imaging test called an ultrasound is very good at picking up fibroids.

But diagnosing endometriosis “is particularly tough,” says Dr. Stacey Missmer, an NIH-funded researcher at Michigan State University. It’s hard to see on imaging tests. No blood tests currently exist that can pick it up. The only way to know that a woman has it for sure is by a surgery in which a doctor looks through a small incision made in the abdomen.

This can lead to a long delay in diagnosis, “in part because no one wants to be quick to do surgery,” Missmer says. Sometimes, if endometriosis is suspected, doctors will prescribe medications first to see if they provide some relief.

Current Treatments

Many drugs used for fibroids, endometriosis, and other disorders that affect the menstrual cycle work by altering certain hormones. Birth control pills and other drugs can block these hormones.

Such treatments may work well for many women, Halvorson explains. “But they can also prevent a woman from getting pregnant,” she says. This can limit how long some women want to use them.

Researchers have developed approaches to treat fibroids that don’t involve major surgery. These often work well. But sometimes, fibroids can come back.

Some women with endometriosis get pain relief from surgery to remove the tissue that’s stuck to other organs. However, other women still have pain after this type of surgery.

For women who don’t get relief from drugs or less invasive procedures, a hysterectomy may be an option. This is surgery to remove the uterus and sometimes the ovaries. Women who undergo this surgery can no longer get pregnant.

Hysterectomy used to be much more widely used than it is now, says Al-Hendy. “But we have alternatives for hysterectomy now. So we tend to use it only when other options haven’t worked,” he explains. However, it doesn’t cure chronic pelvic pain for everyone.

Looking for Better Options

NIH-funded researchers continue to look into new ways to detect, treat, and prevent period problems.

“We need better, noninvasive ways to diagnose endometriosis,” Halvorson says.

Missmer is researching ways to create a test for endometriosis. “Many scientists are now exploring using blood, urine, and saliva,” she explains. “We’re looking for a signal that can determine whether a woman has endometriosis without having to do surgery.”

For both fibroids and endometriosis, “we need nonhormonal treatments,” Halvorson says. These treatments are badly needed, she explains, because “some women can’t tolerate the side effects of hormonal treatments.” And hormonal treatments don’t work for women who want to get pregnant.

Al-Hendy is studying potential new fibroid treatments. His lab has found evidence that lack of vitamin D may play a role in fibroid growth. His team is now developing new drugs based on vitamin D and plans to test them to see if they can shrink fibroids.

Researchers also hope that by understanding the processes in the body that drive period problems, “we can eventually intervene early and prevent them,” Al-Hendy explains.

For now, he adds, there’s a lot to gain from women being aware of how common these disorders are, and of the options already available to treat them.

Missmer stresses the importance of speaking up. “If you were having pain every time you moved your elbow, you wouldn’t hesitate to go to the doctor and discuss it. So, there’s no reason why, if you’re having pain every time you have your period, that shouldn’t be discussed,” she says.

Menstrual Issues

Symptoms of fibroids, endometriosis, or other menstrual problems can include:

• Severe pain in the pelvis
• Very heavy bleeding during periods
• Pain during or after sex
• Feeling pressure in the pelvis
• Frequent need to urinate
• Bowel problems (diarrhea or constipation)

Starting your period — or menstruation — is a major part of puberty and means your body now can make a baby. It also means lots of other changes are going on throughout the month.

Feeling a little confused about your period? Check out the links below to learn what your period is and when it comes. You also can skip to our pages on your menstrual cycle, PMS, how to take care of your period, and what to do if you are having period problems.

Some girls find getting their periods very exciting, and others feel uncomfortable about it. It definitely can take a little getting used to! But lots of women come to see their periods as a wonderful sign that their bodies are healthy and working the way they’re supposed to.

What is your period?

What comes out during your period is the blood and tissue that build up as the lining of your uterus each month.

Your period flow can be light, heavy, or in between. Sometimes menstrual blood also will be different shades of red, from light to dark. You may see some dark clumps or clots of blood, which is normal.

Your period may be heavy the first day or so each time and then decrease on later days.

Periods usually last between three and five days. It is normal to have periods that are shorter or longer, up to seven days. It is also normal if your periods are not the same number of days each month, especially in the first years.

If you think your period is too heavy or have other concerns about your period, see our section on period problems.

At what age do you get your first period?

Usually, girls get their periods between ages 12 and 14, but it can happen years before or after that. Don’t worry if you get your period later or earlier than your friends get theirs — that happens a lot. If you haven’t gotten your period by age 15 (or within three years of when your breasts started to grow), talk to your parents or guardians, your doctor, or another adult you trust.

What causes your period?

Natural body chemicals, or hormones, cause your ovaries to release one egg about once a month. Most months, the egg and the lining of your uterus come out of your vagina as your period. This is part of your menstrual cycle.

This cycle is what makes it possible for a woman to have a baby. During sexual intercourse, the egg can get fertilized by a male’s sperm and then attach to the lining of the uterus (endometrium) and grow into a baby.

Does your period come each month?

Menstrual cycles take place over about one month (around 21 to 34 days), but each woman’s cycle is different. Many women have a cycle that lasts 28 days. Some women may have cycles as long as 45 days.

The cycle includes not just your period, but the rise and fall of hormones and other body changes that take place over the month.

Keep in mind that your periods may not be regular at first. You may have two in one month, or have a month without a period at all. Also, at first your period may last just a couple of days in some months and up to a week in other months. Periods will become more regular in time.

To learn about your own pattern, it's a good idea to keep track of your periods on a calendar or app. Keeping track lets you:

• Get a sense of when to expect your next period
• Know if you missed a period (if it comes on a regular schedule)
• Have a record of your period schedule and when your last one came to share with your gynecologist or other health care provider

When you chart your cycle, remember that it starts with the first day of one period and goes until the first day of the next period.

There are lots of products for taking care of your period. You might decide you like sanitary pads or tampons best. Or, you might decide to use pads sometimes and tampons or menstrual cups other times. Try different products to find the right ones for you.

It’s normal to feel nervous or shy about buying pads or tampons at first. But getting your period is a normal part of life. Need help? Ask your mom, older sister, or someone else you trust which products she likes.

Here’s some great advice about using products for your period: To stay safe, always follow the instructions on the packaging and wash your hands before and after use. And remember to shower or take a bath regularly during your period.

What you should know about pads

• Pads stick to the inside of your underwear and soak up the blood that comes out through the vagina. A sticky strip holds them in place on your underwear.
• Some pads are thinner for days when your period is light, and some are thicker for when you are bleeding more. You can also use these thicker pads at night when you sleep.
• Check your pad every couple of hours during the day to see if it needs changing. You should change it before it is soaked with blood or starts to smell.
• No one can see that you are wearing a pad, so don’t worry about that.
• If you are concerned about any smell, changing pads often and keeping up good hygiene will help control this. You do not need to use deodorant or scented pads (which sometimes can irritate your skin or vagina).
• You can use a panty liner, which is a very thin pad, together with a tampon if you want extra protection. Or you can use a liner alone on light days.
• You probably don’t want to wear pads when you swim. They can soak up lots of water and get bulky, and then can leak when you get out of the water. You could try a tampon instead.

What you should know about tampons

• A tampon goes inside your vagina to soak up blood before it leaves your body. Instructions come with tampons to show you how to put them in. Using tampons sometimes takes practice.
• Some tampons have a plastic or cardboard covering that makes it easier for you to put the tampon in. This is called the applicator. Do not leave the applicator inside your vagina.
• All tampons have a string at the end. This string helps you take the tampon out when it needs to be changed.
• You need to change your tamponat least every four to eight hours. If you think you might sleep for more than eight hours, it's a good idea not to use a tampon overnight.
• Tampons will not get lost in your vagina or “slip up.”
• You can wear tampons when you swim. Water does not enter your vagina.
• If you have trouble putting in a tampon, you might try a smaller one or one with an applicator. If you really cannot get it in, you might see your doctor.
• It is very important to use the tampon with the lowest level of absorbency for your needs.
  • On heavy days, you may need a “super” tampon, and as your flow gets lighter, you may need only a “regular” tampon. Or, you may need a “regular” tampon on heavy days, and then can switch to a “lite” tampon for lighter days.
  • If you remove the tampon after four to eight hours and find that some white material is still showing, you should use a lower absorbency.
  • If a tampon absorbs as much as it can before four hours, you might want to try a higher absorbency.
• Girls who have never had sex can use a tampon. You might try a “slender” tampon at first because they can be easier to put in. What about your virginity? Some people think having a torn hymen (the covering to the vagina) means you aren’t a virgin. Using a tampon might stretch or tear your hymen — or it might not. But doctors say that changes to your hymen do not mean you aren’t a virgin. Having sex means you aren’t a virgin.
• Scented tampons can cause irritation. It’s best not to use scented tampons. If you’re concerned about smell, make sure to wash daily and change your tampon regularly.
• You could be at risk for toxic shock syndrome (TSS) if you use tampons that are too absorbent or don’t change them often enough. You can avoid TSS by not using tampons at all, changing them often, or by switching back and forth between tampons and pads. The symptoms of TSS can be caused by many other illnesses, but make sure to tell an adult and call a doctor if you are using tampons and have the following:
  • High fever that comes on all of a sudden
  • Vomiting or diarrhea
  • Muscle pains
  • Dizziness or fainting
  • A rash that looks like sunburn
  • Redness of eyes, mouth, and throat
  • Strange vaginal discharge (fluid)
  • A feeling of confusion

What is toxic shock syndrome (TSS)?

Toxic shock syndrome (TSS) is a very rare but dangerous illness that affects your whole body. TSS is caused by certain types of bacteria that make poisons. Tampons may make it easier for bacteria to grow in your body, so read our info on using tampons safely. You can also get TSS if bacteria get into an open skin wound, so make sure to clean all wounds well with the help of an adult.

It is important to get medical help right away if you have any of the above symptoms after using a tampon. Doctors treat TSS with antibiotics.

Other ways to care for your period

You may not know about alternative period products that are natural or reusable. Some girls choose items such as menstrual cups or reusable pads because they feel they are better for their bodies and for the environment.

If you’re interested in trying these, you may find them in your local supermarket or drugstore. If not, you can go to a natural foods store or buy them online. Here are some options:

• • Menstrual cups. You put a small cup into your vagina to collect blood. Some cups are for one-time use. Others are emptied, washed well, and reused.
  • Reusable pads. These are pads that are washed and reused. Usually, you would put a cloth pad into a liner that attaches to your underwear. You change the pad as needed and wash it according to the maker’s instructions. These pads are more expensive than disposable ones, but they save money over time because they last for years.
  • Reusable menstrual sponges. These are natural sponges from the ocean floor. They work the same way tampons do. Follow the company’s instructions for changing them (usually after around three to four hours) and washing them. Just like with regular tampons, it may be possible to get toxic shock syndrome from sea sponges.
  • Non-chlorine bleached all-cotton pads and tampons. These are disposable like regular tampons and pads, but they are made without chemicals. They are usually more expensive than other pads or tampons.

In the days leading up to your period, do you have bloating, moodiness, or some other feelings that you’d rather avoid? If so, you are not alone. Many women have uncomfortable feelings starting a week or two before their period that usually stop when their period starts. These feelings can be mild or severe.

Symptoms of PMS are often a normal part of having your period. Doctors generally consider such feelings PMS if they happen month after month and they interfere with some part of your life.

PMS symptoms

You may have some emotional and physical symptoms from PMS. See the chart below for some examples.

What causes PMS?

No one knows for sure what causes PMS, but it seems to be linked to the changes in hormone levels that happen during your menstrual cycle. PMS is not caused by anxiety or depression. They can make your PMS symptoms worse, though, and your PMS can make these conditions worse, too.

Steps to help with PMS

There are many steps you can take to help you feel better. You may need to try different things to figure out what works for you. Your doctor can offer some suggestions.

Consider these tips for dealing with PMS:

• Eat a healthy diet, including foods high in calcium (such as low-fat dairy products), fruits, vegetables, and complex carbohydrates (found in whole grain breads, pasta, and cereals).
• Stay away from salt the few days before your period to help with bloating.
• Drink less caffeine (found in soda, tea, and coffee) to feel less crabby and help ease breast soreness.
• Eat small, frequent meals rather than fewer, big ones.
• Make sure you are getting enough physical activity every day (and not just during your period).
• Make sure to get enough sleep. Try to go to bed and get up the same time each day.

You may have heard that vitamins and other pills such as vitamin B6, vitamin E, magnesium, and calcium can help relieve PMS. It’s important that you talk to your doctor before trying any supplements or herbal treatments.

Medications for PMS

If you are having symptoms of PMS, let your doctor know. There is no cure for PMS, but your doctor can help with the symptoms. In addition to changes in your diet and exercise, he or she may suggest medicines.

Many medicines for menstrual cramps are over-the-counter, so you can buy them without a doctor’s prescription (order). These include pain relievers that have ibuprofen and naproxen . You should talk to your parents/guardians and doctor before taking these. For some medicines, you will need a doctor’s prescription.

Your doctor may suggest diuretics , which help your body get rid of extra fluid. This can help with symptoms like bloating and breast soreness.

Sometimes, a doctor will suggest birth control pills to help with hormones that can affect PMS.

If you’re having strong emotional symptoms, a doctor may also suggest medicines that treat anxiety or depression, such as antidepressants. It can help to talk about your emotions and get support from your family and friends.

How can I keep track of my menstrual cycle?

Use a calendar to keep track of your menstrual cycle. You can mark each day of your period with an "X." Calculate the length of your cycle by counting the days from the first day of bleeding in one period to the first day of bleeding in the next period. In addition to noting the days of your period, it is helpful to make notes about the flow, any pain that is felt, and changes in mood or behavior. Many apps now exist to make tracking your cycle even easier using a smartphone.

What is premenstrual syndrome (PMS)?

PMS is a group of symptoms that are linked to the menstrual cycle. Symptoms usually begin before menstrual bleeding starts and then stop once menstrual bleeding begins. For some women, PMS symptoms include mild cramps or some bloating. For other women, PMS symptoms include severe pelvic pain, headaches, and fatigue.

Can menstrual irregularities make it harder to get pregnant?

Menstrual irregularities can be caused by many different underlying causes. Some of these causes can make it harder to get pregnant, including:

• Polycystic ovary syndrome (PCOS)
• Endometriosis
• Primary ovarian insufficiency (POI)
• Uterine fibroids

Can menstrual irregularities lead to other health problems?

The presence of menstrual irregularities can be a sign of other health problems such as thyroid disease, POI, endometriosis, PCOS, polyps, and uterine fibroids. If left untreated, menstrual irregularities can lead to or contribute to other conditions. These possible conditions vary depending on the type of menstrual irregularity, but some include thickening of the lining of the uterus (called endometrial hyperplasia), low bone density, and iron-deficient anemia.

It is important for a woman with a menstrual irregularity to speak to a health care provider to determine the cause of the irregularity and to receive appropriate treatment as necessary.

When should I see my health care provider about menstrual irregularities?

It is important to contact your health care provider promptly about any significant changes in your menstrual cycle. It is also important to contact your provider if your cycles are associated with significant bleeding or pain, even if your cycle has always been that way. The presence of menstrual irregularities can be indicative of other health problems, such as POI, endometriosis, PCOS, polyps, or uterine fibroids. Your health care provider can order the appropriate tests to diagnose the cause of the menstrual irregularity and provide appropriate treatment.

Can menstrual irregularities lead to cancer?

Menstrual irregularities are often a sign of an underlying condition and, in some cases, the underlying condition may be associated with a higher risk for cancer. For example, absent and irregular periods associated with estrogen production but no progesterone production are associated with endometrial cancer in about 14% of women, if the problem is recurrent. Women who experience irregular periods on a frequent basis may also have a higher risk of ovarian cancer after age 70. Menstrual irregularities such as heavy or prolonged menstrual bleeding are not known to be associated with cancer.