Abnormal Uterine Bleeding

Abnormal uterine bleeding (AUB) is a broad phrase referring to abnormalities in the menstrual cycle outside of pregnancy. Up to one out of three women will develop abnormal uterine bleeding at menarche (the first occurrence of menstruation) or perimenopause (when a woman becomes less fertile, hormones fluctuate). A normal menstrual cycle lasts 2 to 7 days and bleeds 5 to 80 milliliters. Abnormal uterine bleeding occurs when any of these four parameters change.

Last Updated: February 21, 2024

Abnormal uterine bleeding affects 3% to 30% of reproductive-aged women globally, with a higher incidence around menarche and perimenopause. When irregular and intermenstrual bleeding are included, the prevalence climbs to 35% or more.

There are multiple reasons for AUB, including hormonal imbalances, structural abnormality of the uterus, cancer, infections, and other medical conditions.

Hormonal imbalance includes:

  • Anovulation;
  • Thyroid disease;
  • Polycystic ovary syndrome (PCOS).

Structural abnormalities in the uterus include:

  • Polyps;
  • Fibroids;
  • Adenomyosis.

Types of cancer and precancer include:

  • Uterine cancer;
  • Cervical cancer;
  • Vaginal cancer;
  • Ovarian cancer;
  • Endometrial hyperplasia.

There are several abnormal signs of uterine bleeding. Below are a few signs that a woman might be bleeding unusually:

  • Heavy bleeding during periods (formerly called menorrhagia);
  • Bleeding at unexpected times (between periods, after intercourse);
  • Unusual lengths of time (seven days or longer);
  • Irregular menstrual cycles.

Doctors will perform a pelvic examination. They will also request lab tests such as a complete blood count (CBC) to detect anemia and infections. Importantly, bleeding disorders must be tested. Lastly, doctors will also request pregnancy tests and tests for sexually transmitted diseases (STDs).


Depending on the age and symptoms, a woman experiencing AUB may need the following:

  • Ultrasound in the pelvic region to get a picture of pelvic organs.
  • Hysteroscopy is a procedure where a thin, lighted scope is inserted through the vagina and cervix to view the insides of the uterus.
  • In an endometrial biopsy, a piece of the endometrium is taken and looked at under a microscope.
  • Sonohysterography is a procedure where uterine ultrasound pictures are produced as fluid is inserted through a narrow tube.
  • Magnetic Resonance Imaging (MRI)
  • Computed tomography (CT).



Medications and surgery can stop or treat bleeding.

Some of the medicines used to stop abnormal uterine bleeding are:

  • Birth control pills;
  • Progestin;
  • Nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen;
  • Gonadotropin-releasing hormone (GnRH) agonists to stop ovulation;
  • GnRH antagonists can help with heavy-period bleeding caused by fibroids.

Some of the surgery done to address AUB are:

  • Hysteroscopy is a technique to remove fibroids and polyps from the uterus.
  • Uterine arteriography reduces fibroids by stopping blood flow.
  • Myomectomy, where fibroids are removed while the uterus remains intact, sustaining fertility.
  • Endometriosis ablation is when laser, heat, electricity, microwave energy, or freezing destroys the uterine lining. 
  • Hysterectomy or uterus removal, especially when dealing with endometrial cancer.

Many things can cause uncontrollable bleeding in the uterus, but lowering the chances of getting some conditions that cause abnormal bleeding is still possible. For example, keeping a normal weight could help keep hormones in balance. Some types of cancer are less likely to happen if the diet has less animal fat. Having safe sex will make you less likely to get certain sexually transmitted infections (STIs) that can cause the uterus to bleed.

It is also essential that women report to their physician when they experience abnormal bleeding and openly discuss menstruation with them. Such open conversation would help the physician identify obvious signs and inform their patients what should be done.


Davis E, Sparzak PB. Abnormal Uterine Bleeding. [Updated 2022 Sep 9]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK532913/

The American College of Obstetricians and Gynecologist (2022). Abnormal Uterine Bleeding. Retrieved November 1, 2022, from https://www.acog.org/womens-health/faqs/abnormal-uterine-bleeding

Cleveland Clinic (2022). Abnormal Uterine Bleeding. Retrieved November 1, 2022, from https://my.clevelandclinic.org/health/diseases/15428-uterine-bleeding-abnormal-uterine-bleeding#symptoms-and-causes


Last Updated: February 21, 2024