1. Your cycle
  2. Health
  3. Period

Flo Fact-Checking Standards

Every piece of content at Flo Health adheres to the highest editorial standards for language, style, and medical accuracy. To learn what we do to deliver the best health and lifestyle insights to you, check out our content review principles.

Heavy Menstrual Bleeding: Common Signs, Causes, and Treatment Options

Heavy periods are common for lots of people, but most of them don’t have blood loss so severe that it’s categorized as heavy menstrual bleeding. Read on for the answer to the question “what is heavy menstrual bleeding” and learn its common signs, symptoms, causes, and treatment options.

HMB is characterized by having periods with abnormally prolonged or heavy bleeding that interferes with physical, emotional, and social daily life. Heavy menstrual bleeding used to be called menorrhagia, but that word’s not used in medicine anymore.  

If you have HMB, it can be difficult to maintain your normal activities during your periods due to excessive loss of blood that may be accompanied by cramping. About 25 percent of women experience heavy menstrual bleeding. 

If you have HMB, your menstrual flow can be heavy enough to require changing your pad or tampon every hour for several hours in a row. You may also have severe menstrual cramps that may make it difficult to do your usual daily activities. 

Heavy menstrual bleeding can also interfere with well-being and everyday life. According to one study, 68 percent of people with heavy bleeding said that their flow affected their attendance at work or school and that they also tend to disengage from social activities. In the study, 75 percent said they feel less confident during their period, and 84 percent reported avoiding sex.

Though the cause of HMB can’t always be determined, it’s important to be aware of the condition as it may occur due to several underlying issues. 

HMB may also lead to complications like iron deficiency, iron-deficiency anemia, and associated conditions, including severe pain and menstrual cramps.

These symptoms and signs may indicate a heavy menstrual flow:

  • You soak through one or more tampons or pads an hour for several hours in a row. 
  • You have to use two kinds of period products at the same time to control heavy flowing periods. 
  • You have to get up at night to change your sanitary pads or products. 
  • Your periods last longer than eight days.
  • You pass blood clots that are 1 inch (2.5 centimeters) or larger during your periods. 
  • Your periods soak through your bedding or clothes. 
  • You have to restrict your everyday activities because of heavy menstrual bleeding. 
  • You experience symptoms and signs of iron-deficiency anemia, including shortness of breath, fatigue, or tiredness. 

Several methods exist to measure your flow during menses:

  • The alkaline hematin technique: In this technique, the blood present in a used sanitary pad is measured chemically. This is the gold standard to diagnose heavy menstrual bleeding, and blood loss that’s greater than 80 milliliters per cycle is considered heavy. 

To give you an idea of how much 80 milliliters is, a menstrual cup can hold up to around 30 milliliters of menstrual blood, a regular-absorbency tampon absorbs up to five milliliters, and a standard pad absorbs about 15 milliliters. 

  • Pictorial blood loss assessment chart (PBAC): In this technique, you can record the total number of used sanitary products and their level of staining. 

A variety of factors can cause heavy menstrual bleeding. These are some of the most common:

  • Hormonal imbalance: Hormonal imbalance during a menstrual cycle may cause an excess buildup of the endometrial lining, which is shed as heavy menstrual bleeding. Hormonal imbalance may occur due to many conditions, including obesity, polycystic ovarian syndrome (PCOS), thyroid problems, and insulin resistance. 
  • Polyps: Uterine polyps are tiny, benign growths that are sometimes present in the uterine cavity and cervical canal. 
  • Uterine fibroids: These are benign (noncancerous) tumors present in the uterus that may appear during the childbearing years. They can cause prolonged HMB
  • Adenomyosis: In this condition, the inner lining of the uterus embeds in the muscles of the uterus, which can cause HMB. 
  • The intrauterine device (IUD): HMB is one of the common side effects of using a non-hormonal intrauterine device. 
  • Complications of pregnancy: Miscarriage and ectopic pregnancy can cause a single, late, heavy period.
  • Cancer: Cancers of the uterus and cervix can both cause HMB, especially in perimenopausal people. 
  • Bleeding disorders: Heavy menstrual bleeding may occur with some types of bleeding disorders, including von Willebrand’s disease (a disorder in which there is a deficiency or impairment of an essential blood-clotting factor).  
  • Medicines: Certain medicines, including anticoagulants (for example, warfarin), anti-inflammatory medicines, and hormonal medicines such as progestins and estrogen, can sometimes cause HMB.   
  • Other medical illnesses: HMB may occur along with various other medical conditions, including pelvic inflammatory disease (PID) and kidney, thyroid, and liver disease. 

Risk factors for HMB include age and the presence of other medical conditions. Anovulation can cause HMB, typically during the initial year of getting periods. This happens when an egg isn’t released from the ovaries, which causes insufficient progesterone in the body and may result in heavy menses. 

Heavy menstrual bleeding in people of reproductive age beyond their teenage years generally occurs due to a condition in the uterus like fibroids, adenomyosis, or polyps.

HMB treatment is determined by your health care provider based on a variety of factors, including:

  • Your medical history and general health
  • Your capacity to tolerate specific therapies, medicines, or procedures
  • The cause and severity of HMB
  • Your plans for childbearing in the future
  • The effects of heavy menstrual bleeding on your current lifestyle
  • Your personal preference or opinion

Nonsteroidal anti-inflammatory drugs (NSAIDs) may help reduce blood loss and relieve painful cramps. Your health care provider may prescribe oral contraceptives, which might help regulate your menstrual cycles and reduce prolonged or heavy menstrual bleeding. 

A hormonal intrauterine device may also help reduce blood loss and cramping because it releases a type of progesterone that affects the lining of the uterus.

Your health care provider may also prescribe antifibrinolytic medicines to decrease blood flow because they stop clots from breaking down after they’re formed. 

Iron supplements may also be prescribed if you develop signs and symptoms of anemia. 

There are several medical procedures that can be prescribed to manage HMB in some cases.

Dilation and Curettage (D&C): This is a surgical method in which the health care provider removes the topmost layer of the endometrium to reduce heavy menstrual bleeding.

Endometrial resection or ablation: In these two procedures, the health care provider removes some or all of the uterine lining utilizing different techniques to control heavy menstrual bleeding. 

Operative hysteroscopy: In this surgical method, the health care provider uses a specialized tool to see the uterus from the inside to remove fibroids and polyps, correct uterine abnormalities, and remove the uterine lining to control HMB. 

Hysterectomy: This is a major surgical procedure in which the health care provider removes the whole uterus. After this procedure, you won’t be able to get pregnant and won’t get periods. Hysterectomy is used in very rare cases and only when other methods don’t work. 

Heavy menstrual bleeding is the presence of abnormally prolonged or heavy bleeding. With HMB, you may have to change a pad or tampon almost every hour for several hours in a row. You may also have severe painful cramps that can interfere with your usual activities. 

Several medical conditions can cause HMB. Your health care provider may prescribe medication to relieve symptoms or perform surgical procedures, depending upon the cause and severity of your condition and your plans for childbearing.

Magnay, Julia L et al. “Pictorial methods to assess heavy menstrual bleeding in research and clinical practice: a systematic literature review.” BMC women's health vol. 20,1 24. 10 Feb. 2020, doi:10.1186/s12905-020-0887-y

“Heavy Menstrual Bleeding.” Centers for Disease Control and Prevention, 20 Dec. 2017, www.cdc.gov/ncbddd/blooddisorders/women/menorrhagia.html.

“Menorrhagia (Heavy Menstrual Bleeding).” Mayo Clinic, Mayo Foundation for Medical Education and Research, 1 July 2020, www.mayoclinic.org/diseases-conditions/menorrhagia/diagnosis-treatment/drc-20352834.

“Heavy Periods.” NHS Choices, NHS, 7 June 2018, www.nhs.uk/conditions/heavy-periods/.

“Menorrhagia (Heavy Menstrual Bleeding).” Mayo Clinic, Mayo Foundation for Medical Education and Research, 1 July 2020, www.mayoclinic.org/diseases-conditions/menorrhagia/symptoms-causes/syc-20352829.

Herman, Malou C et al. “Diagnosis of heavy menstrual bleeding.” Women's health (London, England) vol. 12,1 (2016): 15-20. doi:10.2217/whe.15.90

“Understanding Your Menstrual Cycle.” Womenshealth.gov, 25 Apr. 2018, www.womenshealth.gov/menstrual-cycle.

“Heavy Periods: Overview.” InformedHealth.org [Internet]., U.S. National Library of Medicine, 4 May 2017, www.ncbi.nlm.nih.gov/books/NBK279294/.

Magnay, Julia L et al. “A systematic review of methods to measure menstrual blood loss.” BMC women's health vol. 18,1 142. 22 Aug. 2018, doi:10.1186/s12905-018-0627-8

Read this next