Table of ContentsView AllTable of ContentsCausesPubertyPerimenopauseLifestyle FactorsHormonal Birth ControlPregnancyPelvic ConditionsEndocrine DisordersTracking Menstrual Cycle Changes
Table of ContentsView All
View All
Table of Contents
Causes
Puberty
Perimenopause
Lifestyle Factors
Hormonal Birth Control
Pregnancy
Pelvic Conditions
Endocrine Disorders
Tracking Menstrual Cycle Changes
A sudden change in menstrual cycle length, either shorter or longer, can result from several conditions and factors.
An average menstrual cycle lasts 28 days—from the first day of menstruation (period bleeding) to the first day of your next period. However, a teen’s cycle can last anywhere from 21 to 45 days and during perimenopause, you may experience similar fluctuations.
Outside of these times, sudden changes in menstrual cycle length are not usually “normal” and may indicate an underlying condition or hormonal changes.
AndreyPopov / Getty Images
Risk Factors for Sudden Menstrual Cycle Length Changes
What Causes Sudden Changes in Menstrual Cycle Length?
Periods are considered irregular in people with a predictablemenstrual cycleunder the following circumstances:
The following circumstances and conditions can cause these irregularities.
Pubertyoccurs when a child experiences the physical and hormonal changes that signal growth to adulthood. Hormonal shifts during this time trigger a menstrual cycle in females.
When youstart having your period, your cycle length can be between 21 and 45 days. Skipping periods during the first couple of years is also common.
If irregularities last more than a couple of years, or if you have long, heavy, painful periods, consult a healthcare provider.
Can You Get Pregnant With Irregular Cycles?If you are sexually active, you can still get pregnant, even with irregular cycles. Consult a healthcare provider about birth control options if you are sexually active or plan to be.
Can You Get Pregnant With Irregular Cycles?
If you are sexually active, you can still get pregnant, even with irregular cycles. Consult a healthcare provider about birth control options if you are sexually active or plan to be.
Perimenopauseis the time leading to menopause (when you stop having periods for 12 consecutive months). It typically begins in your mid to late 40s and lasts several years.
The first sign of perimenopause is irregular periods, which may include:
Other early signs of perimenopause include:
Perimenopause does not require treatment unless your symptoms are bothersome.
The following lifestyle factors can cause changes to an otherwise predictable menstrual cycle:
Hormonal birth controlincludes oral contraceptives (the pill), patches, injections, and implantable devices (IUDs).
Starting, stopping, or changing hormonal birth control can affect cycle length and cause breakthrough bleeding (bleeding between periods) oramenorrhea(absence of a period).This includes minor adjustments like a change in dosing, brands, or a switch to generic.
Birth Control Period BleedingBecausehormonal contraceptives prevent ovulation, the bleeding that occurs differs from a true period. It is withdrawal bleeding due to synthetic hormone variations.
Birth Control Period Bleeding
Becausehormonal contraceptives prevent ovulation, the bleeding that occurs differs from a true period. It is withdrawal bleeding due to synthetic hormone variations.
Consult a healthcare provider if:
Pregnancytypically causes you to miss your period. Variations in menstrual cycles can also occur due to hormonal shifts after delivery or pregnancy loss.
Pregnancy can also causeimplantation bleedingwhen the embryo first burrows into the uterus. This type of bleeding usually occurs about 10 to 14 days after conception.
Implantation bleeding is typically lighter than menstrual bleeding. Some women mistake it for their period because it often occurs around the same time.
If you think you may be pregnant, consider ahome pregnancy testand consult a healthcare provider if it is positive.
PCOS
Polycystic ovary syndrome (PCOS)causes the ovaries to produce extra androgens (a sex hormone more abundant in males than females). One of the most common symptoms is absent periods or shorter or longer than average cycles.
Females with PCOS may only have six to eight periods per year and may also experience the following:
The following may be considered to treat PCOS.
Endometriosis
Endometriosisoccurs when endometrial-like tissue grows outside of the uterus (womb) and can cause:
The first line oftreatment for endometriosisis typically hormonal birth control andnonsteroidal anti-inflammatory drugs (NSAIDs), such as Advil or Motrin (ibuprofen).Ultimately, treatment can include surgical options.
Endometrial Hyperplasia
Endometrial hyperplasiais an abnormal thickening of the lining of the uterine (womb) due to excess estrogen and a lack of progesterone. It can cause:
Possible underlying causes include:
Healthcare providers typically treat endometrial hyperplasia withprogestin, a type of synthetic progesterone in a pill, shot, vaginal cream, or intrauterine device (IUD).
Uterine Fibroids
Uterine fibroidsare benign (noncancerous) growths in the uterus. They can cause:
While not all fibroids require treatment, it is available if your symptoms disrupt daily life and may include the following:
Ovarian Cysts
Ovarian cystsare fluid-filled sacs that grow on the ovaries. Most never cause symptoms and resolve on their own. However, some cause the following:
Healthcare providers often take a wait-and-see approach with ovarian cysts, but it depends on the type and your symptoms.Laparoscopic surgeryto remove cysts is an option, as is the removal of one or sometimes both ovaries.
Pelvic Inflammatory Disease (PID)
Pelvic inflammatory disease (PID)is an infection in the female reproductive organs. It typically occurs due to asexually transmitted infection (STI).
Many women are unaware they have PID because it may not initially cause symptoms. However, PID can lead to the following:
Treatment for PID involves antibiotics. It’s essential to seek treatment quickly as PID can lead to complications such as scarring, infertility, and ectopic pregnancy (pregnancy outside of the uterus).
Endocrine disorders disrupt hormone function and may cause premature ovulation,anovulation(no egg release during ovulation), or changes in menstrual cycle length.
Theendocrine systemincludes the pituitary, thyroid, pancreas, adrenal glands, and ovaries. Example disorders include:
Endocrine disorders typically require medical intervention. If your provider suspects you have one of these disorders, they may send you to anendocrinologistspecializing in hormones.
How to Track Menstrual Cycle Changes
It’s important totrack your periodso you will know what is normal for you. This will make you aware of when you ovulate, when to expect your period, and if something is off.
You can use a calendar, log book, or a period-tracking app to record:
Summary
Sudden changes in your menstrual cycle length could be from stress, overexercising, or dietary changes. Other causes include puberty, pregnancy, perimenopause, hormonal birth control, and health conditions. The average menstrual cycle (time between bleeding) is 28 days. It is irregular when it’s less than 21 or more than 35 days.
When you don’t have a period five days past the expected date, it is considered late. Not having a period for six weeks is considered a missed period. It’s important to track your menstrual period to know when something is different for you.
20 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.The American College of Obstetricians and Gynecologists.Heavy and abnormal periods.MedlinePlus.Vaginal or uterine bleeding.Office on Women’s Health.Your menstrual cycle.Delamater L, Santoro N.Management of the perimenopause.Clinical Obstetrics & Gynecology. 2018;61(3):419-432. doi:10.1097/grf.0000000000000389The American College of Obstetricians and Gynecologists.My periods have changed. Is menopause around the corner?Office on Women’s Health.Period problems.UT Health Houston.How stress can affect your menstrual cycle.Office on Women’s Health.Birth control methods.The American College of Obstetrician and Gynecologists.General approaches to medical management of menstrual suppression.MedlinePlus.Miscarriage.American Pregnancy Association.What is implantation bleeding?UpToDate.PCOS Overview.Foti PV, Farina R, Palmucci S, et al.Endometriosis: Clinical features, MR imaging findings and pathologic correlation.Insights Imaging. 2018;9(2):149-172. doi: 10.1007/s13244-017-0591-0.Becker CM, Bokor A, Heikinheimo O, et al.ESHRE guideline: endometriosis.Hum Reprod Open. 2022;2022(2):hoac009. Published 2022 Feb 26. doi:10.1093/hropen/hoac009.The American College of Obstetricians and Gynecologists.Endometrial hyperplasia.The American College of Obstetricians and Gynecologists.Uterine fibroids.InformedHealth.org [Internet].Ovarian cysts: Overview.Centers for Disease Control and Prevention.About Pelvic inflammatory disease (PID).Ghare Naz MS, Dovom MR, Tehrani FR.The menstrual disturbances in endocrine disorders: A narrative review.International Journal of Endocrinology and Metabolism. 2020;18(4). doi:10.5812/ijem.106694MedlinePlus.Vaginal or uterine bleeding.
20 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.The American College of Obstetricians and Gynecologists.Heavy and abnormal periods.MedlinePlus.Vaginal or uterine bleeding.Office on Women’s Health.Your menstrual cycle.Delamater L, Santoro N.Management of the perimenopause.Clinical Obstetrics & Gynecology. 2018;61(3):419-432. doi:10.1097/grf.0000000000000389The American College of Obstetricians and Gynecologists.My periods have changed. Is menopause around the corner?Office on Women’s Health.Period problems.UT Health Houston.How stress can affect your menstrual cycle.Office on Women’s Health.Birth control methods.The American College of Obstetrician and Gynecologists.General approaches to medical management of menstrual suppression.MedlinePlus.Miscarriage.American Pregnancy Association.What is implantation bleeding?UpToDate.PCOS Overview.Foti PV, Farina R, Palmucci S, et al.Endometriosis: Clinical features, MR imaging findings and pathologic correlation.Insights Imaging. 2018;9(2):149-172. doi: 10.1007/s13244-017-0591-0.Becker CM, Bokor A, Heikinheimo O, et al.ESHRE guideline: endometriosis.Hum Reprod Open. 2022;2022(2):hoac009. Published 2022 Feb 26. doi:10.1093/hropen/hoac009.The American College of Obstetricians and Gynecologists.Endometrial hyperplasia.The American College of Obstetricians and Gynecologists.Uterine fibroids.InformedHealth.org [Internet].Ovarian cysts: Overview.Centers for Disease Control and Prevention.About Pelvic inflammatory disease (PID).Ghare Naz MS, Dovom MR, Tehrani FR.The menstrual disturbances in endocrine disorders: A narrative review.International Journal of Endocrinology and Metabolism. 2020;18(4). doi:10.5812/ijem.106694MedlinePlus.Vaginal or uterine bleeding.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
The American College of Obstetricians and Gynecologists.Heavy and abnormal periods.MedlinePlus.Vaginal or uterine bleeding.Office on Women’s Health.Your menstrual cycle.Delamater L, Santoro N.Management of the perimenopause.Clinical Obstetrics & Gynecology. 2018;61(3):419-432. doi:10.1097/grf.0000000000000389The American College of Obstetricians and Gynecologists.My periods have changed. Is menopause around the corner?Office on Women’s Health.Period problems.UT Health Houston.How stress can affect your menstrual cycle.Office on Women’s Health.Birth control methods.The American College of Obstetrician and Gynecologists.General approaches to medical management of menstrual suppression.MedlinePlus.Miscarriage.American Pregnancy Association.What is implantation bleeding?UpToDate.PCOS Overview.Foti PV, Farina R, Palmucci S, et al.Endometriosis: Clinical features, MR imaging findings and pathologic correlation.Insights Imaging. 2018;9(2):149-172. doi: 10.1007/s13244-017-0591-0.Becker CM, Bokor A, Heikinheimo O, et al.ESHRE guideline: endometriosis.Hum Reprod Open. 2022;2022(2):hoac009. Published 2022 Feb 26. doi:10.1093/hropen/hoac009.The American College of Obstetricians and Gynecologists.Endometrial hyperplasia.The American College of Obstetricians and Gynecologists.Uterine fibroids.InformedHealth.org [Internet].Ovarian cysts: Overview.Centers for Disease Control and Prevention.About Pelvic inflammatory disease (PID).Ghare Naz MS, Dovom MR, Tehrani FR.The menstrual disturbances in endocrine disorders: A narrative review.International Journal of Endocrinology and Metabolism. 2020;18(4). doi:10.5812/ijem.106694MedlinePlus.Vaginal or uterine bleeding.
The American College of Obstetricians and Gynecologists.Heavy and abnormal periods.
MedlinePlus.Vaginal or uterine bleeding.
Office on Women’s Health.Your menstrual cycle.
Delamater L, Santoro N.Management of the perimenopause.Clinical Obstetrics & Gynecology. 2018;61(3):419-432. doi:10.1097/grf.0000000000000389
The American College of Obstetricians and Gynecologists.My periods have changed. Is menopause around the corner?
Office on Women’s Health.Period problems.
UT Health Houston.How stress can affect your menstrual cycle.
Office on Women’s Health.Birth control methods.
The American College of Obstetrician and Gynecologists.General approaches to medical management of menstrual suppression.
MedlinePlus.Miscarriage.
American Pregnancy Association.What is implantation bleeding?
UpToDate.PCOS Overview.
Foti PV, Farina R, Palmucci S, et al.Endometriosis: Clinical features, MR imaging findings and pathologic correlation.Insights Imaging. 2018;9(2):149-172. doi: 10.1007/s13244-017-0591-0.
Becker CM, Bokor A, Heikinheimo O, et al.ESHRE guideline: endometriosis.Hum Reprod Open. 2022;2022(2):hoac009. Published 2022 Feb 26. doi:10.1093/hropen/hoac009.
The American College of Obstetricians and Gynecologists.Endometrial hyperplasia.
The American College of Obstetricians and Gynecologists.Uterine fibroids.
InformedHealth.org [Internet].Ovarian cysts: Overview.
Centers for Disease Control and Prevention.About Pelvic inflammatory disease (PID).
Ghare Naz MS, Dovom MR, Tehrani FR.The menstrual disturbances in endocrine disorders: A narrative review.International Journal of Endocrinology and Metabolism. 2020;18(4). doi:10.5812/ijem.106694
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