Polymenorrhea and Abnormal Uterine Bleeding

Polymenorrhea, which is more accurately described as abnormal uterine bleeding (AUB), is a menstrual cycle abnormality in which a woman experiences uterine bleeding at intervals of less than 21 days.

To put this in perspective, a normal menstrual cycle for an adult woman is 21 to 35 days long, and some sources define it as 24 to 38 days long.

A woman writing on a calendar
effrey Coolidge / The Image Bank / Getty Images

Overview of Abnormal Uterine Bleeding

According to the American College of Obstetricians and Gynecologists (ACOG), abnormal uterine bleeding is defined as bleeding from the uterus that is abnormal in regularity, volume, frequency, or duration. AUB may be acute or chronic, and this definition applies to women who are not pregnant. 


There are many factors that can lead to AUB, and you will need a thorough medical evaluation to identify the underlying cause.

Causes include:

Structural problems: Examples of anatomic problems that may be causing your abnormal menstrual bleeding include fibroids, polyps, endometriosis, endometrial hyperplasia, or certain cancers (for example, uterine cancer).

Hormone imbalances: Various hormone abnormalities may lead to AUB, like thyroid, adrenal, or pituitary gland dysfunction. Polycystic ovarian syndrome is a disorder characterized by hyperandrogenism, ovulatory dysfunction, and polycystic ovaries.

Bleeding disorders: Bleeding disorders like von Willebrand's disease or bone marrow conditions (for example, leukemia) can cause you to bleed and bruise easily, and may lead to excessive uterine bleeding.

Medications: Medications like steroids, chemotherapies, blood thinners, or certain herbal products can affect menstrual bleeding.

Contraceptives: Some birth control methods, including intrauterine devices or birth control pills, may cause abnormal bleeding. 

Infections: Some sexually transmitted infections (for example, chlamydia or gonorrhea) can lead to inflammation of the uterus and abnormal bleeding. 

Systemic illnesses: Liver or kidney disease, anorexia, obesity, or rapid weight changes can lead to abnormal menstrual bleeding.


Your healthcare provider will take a medical history and your gynecologist will need to perform a pelvic examination to inspect your vagina, cervix, uterus, and ovaries.

Your diagnostic evaluation will also include tracking your bleeding pattern to determine whether you've also experienced other irregularities in addition to short intervals between your periods.

Besides polymenorrhea, other patterns of abnormal uterine bleeding include:

  • Oligomenorrhea: Menstrual cycle length that is greater than 37 days
  • Amenorrhea: Not having a period for six months
  • Menorrhagia: Heavy bleeding during your periods
  • Metrorrhagia: Bleeding or spotting in between your periods
  • Menometrorrhagia: Longer duration of menstrual bleeding that occurs at unpredictable intervals
  • Postmenopausal bleeding: Bleeding that happens more than 12 months after a woman's last menstrual cycle
  • Postcoital bleeding: Bleeding or spotting after sex

Based on your history and physical examination, your healthcare provider will decide which diagnostic tests you will need. These can include a pregnancy test, blood tests, a transvaginal ultrasound, a hysteroscopy, or an endometrial biopsy (a small piece of tissue is removed from your uterus to be examined under a microscope).


Your treatment will depend on the cause of your bleeding. If you have a sexually transmitted infection, you may need treatment with antibiotics, and if you have a benign uterine growth, it might need to be removed.

The cause of your AUB could be secondary to an illness that is outside your reproductive system. For example, if you have thyroid disease, you would need your thyroid condition treated—and this may alleviate your AUB.

After your healthcare provider has performed a thorough examination and has evaluated your diagnostic tests, it might turn out that there isn't anything abnormal about your increased frequency of menstruation. For some women, a shorter-than-average menstrual cycle is normal, and the precise "why" may remain unclear. 

If you are bothered by your frequent menstrual cycles or if the bleeding has caused you to become anemic, your healthcare provider may recommend a combined hormonal contraceptive to lengthen the intervals between bleeding. Another option is to use a contraceptive method that temporarily stops the menstrual flow or makes bleeding very light, such as MirenaDepo-Provera, or Nexplanon.


If your AUB doesn't need to be treated, or if you continue to have excessive bleeding despite treatment, you can be susceptible to anemia due to blood loss. Symptoms of anemia include pale skin, weakness, fatigue, lightheadedness, and shortness of breath.

Your healthcare provider might monitor you for anemia with blood tests at regular intervals so you can be treated for it if needed.

Your practitioner may recommend a change of diet or might prescribe iron supplements to help prevent and manage anemia.

A Word From Verywell

It's important to see your healthcare provider if you are experiencing a change in your menstrual cycle.

You may want to try tracking your period before your appointment, using either an app on your phone or a calendar. As well as marking the dates of your bleeding, it's helpful to note the severity of bleeding (light, medium, or heavy).

6 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.
  1. Long WN. Abnormal Vaginal Bleeding. In: Walker HK, Hall WD, Hurst JW, editors. Clinical Methods: The History, Physical, and Laboratory Examinations. 3rd edition. Boston: Butterworths; 1990. Chapter 173. 

  2. ACOG committee opinion no. 557: Management of acute abnormal uterine bleeding in nonpregnant reproductive-aged women. Obstet Gynecol. 2013;121(4):891-6. doi:10.1097/01.AOG.0000428646.67925.9a

  3. American College of Obstetricians and Gynecologists. Abnormal Uterine Bleeding.

  4. American College of Obstetricians and Gynecologists. Polycystic ovary syndrome.

  5. Nebgen DR, Rhodes HE, Hartman C, Munsell MF, Lu KH. Abnormal Uterine Bleeding as the Presenting Symptom of Hematologic CancerObstet Gynecol. 2016;128(2):357–363. doi:10.1097/AOG.0000000000001529

  6. National Heart, Lung, and Blood Institute. Anemia.

By Tracee Cornforth
Tracee Cornforth is a freelance writer who covers menstruation, menstrual disorders, and other women's health issues.