Pain that you get with your menstrual period is called dysmenorrhea (dis-men-uh-REE-uh). Pain is the most common problem women have with their periods. More than half of women who have periods get some pain around their period.² Some women may get just a feeling of heaviness in the abdomen or tugging in the pelvic area. Other women experience severe cramps different from premenstrual syndrome (PMS) pain.

A majority of period pain can be relieved by over-the-counter nonsteroidal anti-inflammatory drugs (NSAIDs) such as naproxen, ibuprofen, or aspirin.³ Starting an over-the-counter NSAID medicine when your period first starts may also lessen heavy menstrual bleeding⁴ and help control the pain better.

There are two types of dysmenorrhea:

• Primary dysmenorrhea. This is the most common type of dysmenorrhea. The pain is usually caused by contractions of the uterus (womb). The uterus contracts during your period to help the uterine lining leave the body. Teens may get dysmenorrhea soon after they get their first period. For most women, primary dysmenorrhea gets less painful as they get older. But some women get severe menstrual pain. Your risk for dysmenorrhea may be higher if you:⁵
  • Got your first period before age 11
  • Have longer or heavier periods
  • Smoke
  • Have high levels of stress^6,7

• Secondary dysmenorrhea. This type of dysmenorrhea is usually caused by another health problem. Pain from secondary dysmenorrhea usually gets worse as you get older. It also lasts longer than normal menstrual cramps. Problems that cause secondary dysmenorrhea include:
  • Endometriosis. This condition happens when the lining of the uterus grows outside of the uterus where it does not belong. In response to monthly changes in levels of the hormone estrogen, this lining breaks down and bleeds outside of the uterus and can cause swelling and pain.
  • Uterine fibroids. Fibroids are tumors that grow in or on the wall of the uterus. They are almost always not cancerous. Some women with fibroids experience pelvic pain and vaginal bleeding at times when they do not have their period.
  • Ovarian cysts. Cysts are fluid-filled sacs on the ovary. Ovarian cysts usually don’t cause any symptoms, but some can cause pain during your period or at ovulation.

When to see your doctor

Talk to your doctor or nurse if over-the-counter pain medicine, such as ibuprofen or naproxen, does not help or if the pain interferes with daily activities like work or school. Your doctor or nurse will ask you questions and do some tests, including possibly a physical exam, to rule out any other health problem. Keeping track of your symptoms and periods in a diary or calendar can help your doctor or nurse diagnose any health problems.

See your doctor to rule out other health problems if:

• You have blood clots in your menstrual flow that are larger than a quarter.
• Your pain happens at times other than just before your period or during your period.

Treatment depends on what is causing your pain. Your doctor may prescribe hormonal birth control, such as a hormonal intrauterine device (IUD),⁸ the pill, shot, or vaginal ring,⁹ to help with pain from endometriosis, fibroids, or ovarian cysts. Hormonal birth control is sometimes prescribed by doctors for women’s health concerns other than preventing pregnancy. You may also need surgery, as a last resort, if one of these conditions is causing your pain.

Your periods are considered irregular if your menstrual cycle is shorter or longer than average. This means that the time from the first day of your last period up to the start of your next period is less than 24 days or more than 38 days.

Your periods can also be irregular if your cycle length varies by more than 20 days from month to month.¹⁰ An example would be your cycle jumping from a normal 25-day cycle to a 46-day cycle the next month and then back to a 25-day cycle the following month.

Irregular periods are normal for teenage girls and perimenopausal women. Teen girls’ periods may be irregular for the first few years before becoming more regular. During the transition to menopause, called perimenopause, menstrual cycles may become more irregular over time.

Causes of irregular periods include:

• Eating disorders. Irregular or missed periods can be signs of eating disorders, most often anorexia nervosa. But any eating disorder, including bulimia nervosa and binge eating disorder, can cause irregular periods.
• Thyroid problems, such as hyperthyroidism (hy-pur-THY-roi-diz-uhm). Hyperthyroidism, or overactive thyroid, causes your thyroid to make more thyroid hormone than your body needs. Hyperthyroidism can also cause fewer and lighter menstrual periods than normal.
• High amounts of prolactin in the blood. This condition is called hyperprolactinemia (hy-pur-pro-LAK-te-nee-me-uh). Prolactin is the hormone that causes breasts to grow during puberty and makes breastmilk after childbirth. It also helps control the menstrual cycle.
• Certain medicines, such as those for epilepsy or anxiety
• Polycystic ovary syndrome (PCOS), a condition that usually causes multiple ovarian cysts, hormonal imbalance, and irregular periods. About 1 in 10 women with irregular menstrual cycles has PCOS.¹
• Primary ovarian insufficiency (POI). POI happens when your ovaries stop working normally before age 40. It can happen as early as the teenage years. POI is not the same as premature menopause. Unlike women who go through premature menopause, women with POI may still have periods, though they are most often irregular. Women with POI may also still get pregnant.
• Pelvic inflammatory disease (PID). Irregular periods can be a sign of PID, an infection of the reproductive organs. PID is most often caused by a sexually transmitted infection (STI).
• Stress. Studies show high levels of chronic (long-term) stress can lead to irregular periods.¹¹
• Uncontrolled diabetes. Type 1 and type 2 diabetes can cause irregular periods, but getting your diabetes under control can help your periods become more regular.¹²
• Obesity. The extra fat in the body makes the hormone estrogen. The extra estrogen changes the normal menstrual cycle and can cause missed, irregular, or heavy periods.

When to call the doctor

• You get irregular periods after having normal cycles.
• Your period happens more often than every 24 days or less often than every 38 days.

Treatment depends on the cause of the irregular periods. Your doctor may give you hormonal birth control, such as a hormonal IUD,⁸ the pill, shot, or vaginal ring,⁹ to help control your menstrual cycle. Hormonal birth control is sometimes prescribed by doctors for women’s health concerns other than preventing pregnancy.

Heavy periods affect one in five American women each year.¹³ If you have heavy bleeding, your periods may be so painful and heavy that you find it hard to do normal activities such as going to work or school.

Causes of heavy bleeding include:

• Problems with ovulation. In a normal menstrual cycle, your uterine lining builds up and thickens to prepare for pregnancy. If pregnancy does not happen, the uterine lining leaves your body during your period. If your hormones get out of balance or if you do not ovulate, the uterine lining can build up too much and bleed heavily and in an unpredictable pattern.
• Problems with the uterine lining. If your hormones or uterine lining get out of balance, the uterine lining can bleed too much. This can cause heavy bleeding as the lining is pushed out during the next menstrual period.
• Thyroid problems. Heavy bleeding can be a sign of hypothyroidism (hy-poh-THY-roi-diz-uhm), or underactive thyroid. Hypothyroidism happens when your thyroid does not make enough thyroid hormones.
• Uterine fibroids. Fibroids are made of muscle tissue that grows in or on the wall of the uterus. They are almost always not cancer. They can cause pain and heavy or irregular bleeding.
• Uterine polyps. Polyps are an overgrowth of the endometrial tissue that lines the inside of the uterine wall. They are usually small. They are usually not cancer but can cause heavy or long periods.
• Certain medicines. Some medicines, such as blood thinners, can cause heavy or long periods.
• Pregnancy problems. Unusual or not regular heavy bleeding can be caused by a miscarriage (an early pregnancy that ends) or an ectopic pregnancy.  An ectopic pregnancy is when the fertilized egg implants outside of the uterus (womb) where it does not belong, putting a woman’s life in danger. Ectopic pregnancies can never end in a healthy pregnancy and are a medical emergency.
• Bleeding disorders. Hemophilia and von Willebrand’s disease are inherited bleeding disorders that cause heavy bleeding during periods. Studies show that up to one in five white women with heavy periods has a bleeding disorder. Bleeding disorders are less common in African-American women, affecting about one in 20 African-American women with heavy bleeding.¹⁴ For many women, heavy menstrual bleeding is the only sign they have a bleeding disorder.
• Obesity. The extra fat in the body makes the hormone estrogen. The extra estrogen changes the normal menstrual cycle and can cause missed, irregular, or heavy periods.

Some research has found that women with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) have a higher risk for heavy bleeding.¹⁵ Women with ME/CFS may experience a range of symptoms that can include fatigue (tiredness or exhaustion that does not get better with rest and sleep), muscle and joint pain, and memory problems.

When to call the doctor

• Your period lasts longer than eight days.
• You bleed through one or more pads or tampons every one to two hours.
• You feel dizzy, lightheaded, weak, or tired, or if you have chest pain or trouble breathing during or after your period. These can be symptoms of anemia. Anemia is a condition that happens when your blood cannot carry enough oxygen to your body because of a lack of iron.
• You pass menstrual blood clots larger than the size of quarters. (It is normal to pass clots the size of quarters or smaller.)                 

Your doctor or nurse may try treating heavy bleeding first with hormonal birth control, such as a hormonal IUD,⁸ the pill, shot, or vaginal ring.⁹ Hormonal birth control is sometimes prescribed by doctors for women’s health concerns other than preventing pregnancy. Your doctor may also suggest trying over-the-counter pain relievers, such as naproxen or ibuprofen, which may lessen bleeding for some women, especially when taken immediately before your period starts or as soon as your period starts.

If birth control or other medicines do not help, you may need surgery to treat the cause of heavy bleeding. Surgery for heavy bleeding is usually the last treatment option women and their doctors consider because surgery always has risks.

Unusual or abnormal bleeding is any bleeding that is different from your typical menstrual period or happens when you do not have your period.

Causes of unusual bleeding include:

• Hormonal changes. Changing hormone levels during puberty and perimenopause, the transition to menopause, can cause longer, heavier periods. They can also cause irregular cycles.
• Endometriosis. This condition happens when the lining of the uterus grows outside of the uterus where it does not belong.
• Ovarian cysts. Unusual bleeding may be a sign of an ovarian cyst that has ruptured (burst).
• Cancer, such as uterine, cervical, and ovarian cancer. Any vaginal bleeding after menopause can be a sign of a serious health problem, including ovarian, cervical or uterine cancer.

When to see the doctor

You should see your doctor if you have unusual bleeding. This may include:

• Bleeding after sex, more than once
• Spotting or bleeding anytime in the menstrual cycle other than during your period
• Bleeding during your period that is heavier or lasts longer than normal
• Bleeding after menopause

Your doctor may start by checking for problems that are most common in your age group. Some of these are not serious and are easy to treat. Your doctor may prescribe hormonal birth control, such as a hormonal IUD, the pill, shot, or vaginal ring, to help control your menstrual cycle. Hormonal birth control is sometimes prescribed by doctors for women’s health concerns other than preventing pregnancy. Other types of bleeding, such as any vaginal bleeding after menopause, can be more serious.

The absence of menstrual periods before menopause is called amenorrhea (ay-men-uh-REE-uh). You may have amenorrhea if you:

• Haven’t had a period for three months in a row
• Haven’t had your first period by age 15

Amenorrhea happens in 3% to 4% of women.¹⁶

Amenorrhea that is not caused by pregnancy or breastfeeding could mean that your ovaries stopped making normal amounts of the hormone estrogen. Missing this hormone can have serious effects on your health.

Causes of amenorrhea include:

• Pregnancy. Your period stops during pregnancy because your ovaries no longer release eggs. You may get some spotting (light vaginal bleeding), but this is common and usually does not mean a problem with the pregnancy. If you have spotting during pregnancy you should see your doctor or nurse to be sure. Learn more in our Pregnancy section.
• Breastfeeding. For some women, their periods do not come back until after breastfeeding ends. For others, their periods may return within a few months of giving birth. While your baby transitions from breastfeeding to other foods you may ovulate and not realize it. All women should talk to their doctor or nurse about birth control methods during breastfeeding if they do not want to get pregnant again right away. Learn more in our Breastfeeding section.
• Eating disorders, especially anorexia nervosa. Amenorrhea can happen if your body fat drops so low that ovulation stops. Anorexia often causes extreme weight loss leading to a very low body weight that is not healthy. This can cause periods to be less regular or stop completely.
• Weight. Gaining too much weight or losing too much weight can cause missed periods. Menstrual periods will usually restart after losing weight if you are overweight or gaining weight if you are underweight.
• Stress. Long-term, severe stress can affect the part of your brain that controls reproduction. As a result, ovulation and your period can stop. Managing the stress can help restore normal menstrual cycles.¹¹
• Hormonal problems. This includes problems with the reproductive organs or those caused by health conditions such as polycystic ovary syndrome (PCOS).
• Other serious health problems, including birth defects and tumors in the brain. Once these problems are treated, your period may start for the first time or you may get your period again if it had stopped.

When to call the doctor

• You have gone three months without a period and are not pregnant or breastfeeding.
• You have not gotten your period by age 15.
• You have not started your period within three years after breast growth began, or if breasts haven’t started to grow by age 13.

About four in 10 women will get a migraine (a painful, severe headache) in their lifetime. About half of those women report that their migraine happens around their periods.¹⁷

Researchers are not sure what causes migraine. Many factors can trigger migraine, including stress, anxiety, and bright or flashing lights. Also, hormones that control the menstrual cycle may affect headache-related chemicals in the brain.¹⁸

When to see the doctor

See your doctor if you think you have migraine headaches. If you already know you have migraine, you should schedule an appointment if:

• Your headaches change.
• Treatments that once worked no longer help.
• You have side effects from your medicine.
• You take hormonal birth control pills and have migraine with aura (seeing bright flashing lights or spots that aren’t real).¹⁸
• Your headaches are worse when you lie down.

Migraine cannot be cured, but your doctor can help you manage them. A key step is identifying what triggers a migraine and planning how to avoid these triggers.

Your doctor may prescribe medicine to reduce the number of migraines. Medicines may include antidepressants, blood pressure medicines, certain types of hormonal birth control, and seizure medicines. Botox injections may also help prevent migraine.

Other medicines can help when a migraine starts. These include over-the-counter pain medicines and prescription medicines. Learn more on our Migraine page. 

For more information about period problems, call the OWH Helpline at 1-800-994-9662 or check out the following resources from other organizations:

• Abnormal Uterine Bleeding – Information from the American Society for Reproductive Medicine
• Amenorrhea – Information from the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
• Heavy Menstrual Bleeding – Information from the Centers for Disease Control and Prevention
• Menstrual Cramps – Information from the Mayo Clinic
• Menstrual Irregularities – Information from NICHD
• Irregular Menstrual Periods – Information from the Harvard Medical School
• Painful menstrual periods – Information from the National Library of Medicine

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