Heavy Menstrual Bleeding Causes and Diagnosis

It's a common condition, but one that warrants a doctor's evaluation

Heavy Menstrual Bleeding Can Impact Your Quality of Life
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Experiencing heavy or prolonged menstrual bleeding—the medical term is menorrhagia—can be alarming and nerve-wracking. While this is a common experience, heavy menstrual bleeding does warrant a visit to your doctor, preferably your gynecologist.

Am I Experiencing Heavy Menstrual Bleeding?

The easiest way to know if you are experiencing heavy menstrual bleeding is to take note of how often you are soaking through a pad or tampon.

If your period is heavy enough to require changing a pad or tampon every hour for several hours, or if you have a vaginal bleeding that lasts more than a full week, you are experiencing heavy menstrual bleeding.

Besides these two, other signs of heavy menstrual bleeding include:

  • Wearing more than one pad at a time in order to control the bleeding
  • Having to change your tampon or pad in the middle of the night
  • If your menstrual blood contains clots that are the size of a quarter or bigger


Diagnosing the cause of heavy menstrual bleeding can be a bit of a tedious process, so it's best to be prepared. Before your appointment, try to jot down your period pattern in the last few months. For instance, how many days did you bleed each month? How many pads or tampons do you go through on the days of your heaviest menstrual flow?

In addition, it's a good idea to make a list of all your medications, including hormonal birth control, any hormone therapy, and any vitamins or over-the-counter supplements.

In figuring out why you are bleeding heavily, do not be surprised if your doctor orders a series of tests, in addition to performing a pelvic exam. These tests may include:

  • a pregnancy test (if premenopausal)
  • blood tests (for example, a complete blood count, iron levels, and thyroid hormone)
  • an ultrasound of your pelvis

    Your doctor may also perform a procedure in the office called a hysteroscopy in order to visualize the inside of your uterus. She may also take a sample of your uterine tissue, called an endometrial biopsy, depending on your age and your individual symptoms.


    There are a number of different causes for heavy menstrual bleeding—some benign (non-cancerous) like fibroids, and some more serious like cancer of the uterus or cervix. Other causes are not structural but have to do with hormone changes or bleeding problems within your body.

    Ovulatory Dysfunction

    Ovulatory dysfunction during adolescence or perimenopause is the most common cause of heavy menstrual bleeding. During this time, a woman may ovulate (release an egg) irregularly, which means not every month or not at all. This leads to thickening of the uterine lining and heavy periods.

    Ovulatory dysfunction can also occur with certain medical conditions like hypothyroidism, polycystic ovarian syndrome, and premature ovarian failure. Treating the underlying problem (for example, an underactive thyroid) is critical to restoring normal ovulation and normalizing a woman's periods.

    If irregular ovulation is part of the body's normal response (for example, puberty or perimenopause), birth control methods or hormone therapy, respectively, can usually ease up the bleeding.

    Uterine Fibroids 

    Fibroids are usually benign (non-cancerous) growths that develop from the muscle of a woman's uterus and are most common during a woman's 30s or 40s. While the cause of uterine fibroids is unclear, it is known that they are estrogen-dependent. This is why certain hormonal birth control methods like birth control pills can help reduce heavy menstrual bleeding from fibroids. Progestin-release intrauterine devices (for example, Mirena) can decrease menstrual bleeding, but they do not actually reduce fibroid size.

    Another medication sometimes used to treat fibroids is a gonadotropin-releasing hormone (GnRH) agonist, a medication that decreases the size of fibroids but can only be used for a short period of time, due to side effects.

    Also, several surgical treatments are available to treat fibroids, including myomectomy (removal of the fibroid), endometrial ablation for small fibroids (the lining of the uterus is destroyed), and uterine artery embolization (the blood supply is cut off to the fibroid). In the most severe cases, a hysterectomy may be warranted, in which the whole uterus is removed either with or without the ovaries.

    Often, when symptoms are not severe or troublesome, it's sufficient to take a “wait and see” approach with uterine fibroids. And once menopause occurs, tumors typically shrink and disappear without treatment.

    Uterine Polyps 

    Polyps in the uterus—called endometrial polyps—are typically non-cancerous, grape-like growths that protrude from the lining of the uterus. They can occur in both premenopausal and postmenopausal women. The cause of endometrial polyps is unclear, though research suggests a link between postmenopausal hormone therapy and obesity.

    Treatment for endometrial polyps may involve polyp removal. A pathology lab will evaluate endometrial polyps for cancer following their removal.

    Uterine Adenomyosis
    In this condition, the uterus becomes enlarged because cells of the uterus grow into the muscular wall of the uterus, causing painful and heavy bleeding. While bleeding can be reduced with hormonal birth control methods, the definitive treatment for adenomyosis is a hysterectomy.

    Pelvic Inflammatory Disease (PID)

    PID is most often caused by an untreated sexually transmitted infection, however, it can sometimes occur following childbirth, abortion, or other gynecological procedures. In PID, one or more reproductive organs are infected, like the uterus,  fallopian tubes, and/or cervix.

    The recommended treatment for PID is antibiotic therapy.

    Cervical Cancer

    This is a type of cancer that occurs when cells in the cervix become abnormal, multiply out of control, and damage healthy parts of the body. The human papillomavirus, or HPV, is the cause of the vast majority of cervical cancers.

    Treatment for cervical cancer includes surgery, chemotherapy, and/or radiation therapy.

    Endometrial Cancer

    This cancer occurs when abnormal cells in the endometrium (the lining of the uterus) multiply out of control and damage the uterus and other organs. While the cause of endometrial cancer is unknown, women diagnosed with this type of cancer tend to be in their mid-60s.

    The first treatment for endometrial cancer is usually a hysterectomy, possibly followed by chemotherapy and/or radiation treatments.

    Bleeding Disorders

    While there are several types of bleeding disorders, the most common type in women is von Willebrand Disease or VWD. Treatments for von Willebrand Disease involve the release of stored clotting factors in the blood or, in extreme cases, replacing the clotting factor with an intravenous (through the vein) treatment or with a prescribed nasal spray.

    Other bleeding problems like having a low platelet count (platelets are involved in the clotting process and are produced in the bone marrow) or being on a blood thinner like Coumadin (warfarin sodium) can also be the culprit behind heavy menstrual bleeding.

    Other Causes of Heavy Menstrual Bleeding

    You may be surprised to know that besides this extensive list, there are other causes of heavy menstrual flow. This only emphasizes the importance of seeing your doctor for a proper diagnosis and evaluation.

    Of course, if you are having severe, acute bleeding, you may need to go to the emergency room—an indication would be if you are soaking through four or more pads or tampons in a two hour period. If you are pregnant, seek out immediate medical care with any bleeding.

    Besides the ones mentioned above, other potential causes of heavy menstrual bleeding in non-pregnant women include endometriosis and having an intrauterine device (IUD) like the Mirena, especially during your first year of use.

    A Word From Verywell

    Getting to the bottom of your heavy menstrual bleeding is important not only for your quality of life but for your health as well. Heavy blood loss, regardless of the cause, can cause iron deficiency anemia, which can make you short of breath, tired, and dizzy. Once both the bleeding and the root cause of your bleeding are addressed and treated, you can move forward and feel well—you deserve it.


    American College of Obstetrics and Gynecology. (April 2013, reaffirmed 2015), Committee Opinion: Management of Acute Abnormal Uterine Bleeding in Nonpregnant Reproductive-Aged Women.

    American College of Obstetrics and Gynecology. (June 2016). Frequently Asked Questions: Heavy Menstrual Bleeding.

    Hauk L et al. ACOG Releases Guidelines on Management of Abnormal Uterine Bleeding Associated with Ovulatory Dysfunction. Am Fam Physician. 2014 Jun 15;89(12):987-88.

    Kaunitz AM. Approach to abnormal uterine bleeding in nonpregnant reproductive-age women. (October 2016). In: UpToDate, Barbieri RL, Levine D (Eds), UpToDate, Waltham, MA.