Causes of Heavy Bleeding During Your Period

Heavy menstrual bleeding (previously known as menorrhagia) can be caused by a number of medical issues, including fibroids, uterine polyps, perimenopause, and other factors. 

Chronic (prolonged) or heavy periods can lead to complications such as iron-deficiency anemia. Fortunately, heavy periods can be treated with medication, contraceptives, and surgery.

This article discusses the symptoms and causes of heavy menstrual bleeding. It defines normal and heavy periods. It also explains when you should talk to your gynecologist and when emergency medical care may be required.

Signs You're Losing Too Much Blood During Period

A typical period lasts four or five days. During that time, an individual sheds 2 to 3 tablespoons of blood. Those with heavy menstrual bleeding can lose twice as much blood each month.

These are signs that you're losing too much blood during your period and should see a healthcare provider:

• Bleeding for seven or more days
• Needing to change a pad or tampon every hour for several hours
• Wearing more than one pad at a time in order to control the bleeding
• Passing menstrual blood that contains clots that are the size of a quarter or bigger

What Causes Heavy Menstrual Bleeding?

There are a number of different causes of heavy menstrual bleeding—including benign (noncancerous) growths, like fibroids, or malignant growths, like cancer of the uterus or cervix. Hormone changes or blood clotting disorders can cause heavy menstrual bleeding too.

Other less common causes of heavy menstrual bleeding include endometriosis and having an intrauterine device (IUD) like the ParaGard, which may cause excessive bleeding, especially during your first year of use.

But the list does not stop there. That's why it's important to see a healthcare provider for a proper diagnosis and evaluation.

Ovulatory Dysfunction

The most common cause of heavy menstrual bleeding is ovulatory dysfunction during adolescence or perimenopause. During this time, ovulation (releasing an egg) can be irregular—which means it might not happen every month. This can lead to thickening of the endometrium (uterine lining) and heavy periods.

Oral contraceptives can usually regulate your bleeding during adolescence, and hormone therapy can help during menopause.

Beyond the normal hormonal changes that occur with puberty or menopause, hormonally-induced ovulatory dysfunction can also occur with:

• Hypothyroidism
• Polycystic ovary syndrome (PCOS)
• Premature ovarian insufficiency

Getting treated for your underlying problem is important, and it can help restore regular ovulation and normalize your periods.

Uterine Fibroids

Fibroids are growths that develop from the muscle of the uterus, usually between the ages of 30 and 49.

Uterine fibroids need estrogen to grow. Hormonal birth control methods, like birth control pills, can help reduce heavy menstrual bleeding from fibroids.

Some of the treatments for uterine fibroids include the following:

• Progestin-releasing intrauterine devices (IUDs) can decrease menstrual bleeding but do not reduce fibroid size.
• Injectable gonadotropin-releasing hormone agonists can decrease the size temporarily but can only be used for a short time due to their side effects.
• Endometrial ablation (in which the lining of the uterus is destroyed) is a procedure that can be used for the treatment of heavy menstrual bleeding.
• Myomectomy is surgical removal of the fibroid.
• Uterine artery embolization is a surgery that cuts off the blood supply to the fibroid.

In the most severe cases, a hysterectomy may be warranted, in which the uterus is removed, with or without the ovaries.

Uterine Polyps

Endometrial polyps are typically noncancerous, grape-like growths that protrude from the lining of the uterus. They can develop before and after menopause. The cause of endometrial polyps is unclear, though research suggests a link between hormone therapy and obesity.

Uterine Adenomyosis

Uterine adenomyosis is a condition in which the endometrial uterine cells grow into the muscular wall of the uterus, causing uterine enlargement and painful, heavy bleeding. Hormonal birth control methods can help control the condition, and the definitive treatment for adenomyosis is a hysterectomy.

Pelvic Inflammatory Disease (PID)

PID is most often caused by an untreated sexually transmitted infection (STI), however, it can sometimes occur following childbirth, abortion, or other gynecological procedures. In PID, one or more reproductive organs can be infected—including the uterus, fallopian tubes, and/or cervix. The recommended treatment for PID is antibiotic therapy.

Cervical or Endometrial Cancer

Cervical cancer, which can be caused by human papillomavirus (HPV) (an asymptomatic STI), can invade other parts of the body. There are a few different treatment options for cervical cancer including:

• Surgery
• Chemotherapy
• Radiation therapy

Endometrial cancer occurs when abnormal cells in the endometrium grow into the uterus and/or other organs. While the cause of endometrial cancer is unknown, the most common age for diagnosis is the mid-60s.

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 (VWD). Treatments for von Willebrand disease involve releasing stored clotting factors in the blood or, in extreme cases, replacing the clotting factor with an intravenous or a prescribed nasal spray.

Other bleeding issues that can lead to heavy menstrual bleeding include:

• Having a low platelet count (platelets are involved in the clotting process and are produced in the bone marrow)
• Taking a blood thinner like aspirin or warfarin

Pregnancy Complications

Early pregnancy complications can cause heavy bleeding that mimics period bleeding. The most common are:

• Ectopic pregnancy: This occurs when a fertilized egg implants outside of the uterus. If the egg implants in a fallopian tube, the tube can rupture, causing heavy bleeding. Ectopic pregnancy is an emergency.
  
• Miscarriage: Early pregnancy loss or miscarriage is a common cause of bleeding during early pregnancy. 
  

Certain Medications

Certain medications may cause heavier menstrual bleeding. Some examples include:

• Anticoagulants (blood thinners): Any medication that thins the blood can lead to heavy menstrual bleeding. Some examples include non-steroidal anti-inflammatory drugs (NSAIDs), Bayer (aspirin), heparin, and warfarin.
• Antidepressants: Taking antidepressants, especially SSRIs and SNRIs, increases the risk of menstrual disorders, including heavy menstrual bleeding.
• Antipsychotics: Medications such as Risperdal (risperidone) and Haldol (haloperidol) can cause abnormally high levels of the hormone prolactin. This may cause heavy menstrual bleeding and other problems with menstruation.
• Corticosteroids: Corticosteroid injections are often used to treat inflammation, but may also cause abnormally heavy menstrual bleeding.
• Certain medicinal herbs: Ginseng, chaste berry, and danshen may cause abnormal uterine bleeding, including heavier periods.
• Tamoxifen: This breast cancer drug blocks the actions of estrogen. It can also contribute to heavy menstrual bleeding.
• Intrauterine contraceptive devices (IUD): Heavy menstrual bleeding is a frequently reported IUD side effect.
  
• Hormone replacement therapy: People taking hormone replacement therapy to treat menopausal symptoms may experience irregular bleeding, which can sometimes be heavy.
  

When to Call a Healthcare Provider

It's important that you get a diagnosis for the cause of your heavy menstrual bleeding. Before your appointment, 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?

Make sure you have a list of all your medications, including hormonal birth control, hormone therapy, and any vitamins or over-the-counter supplements.

You might have diagnostic tests, such as:

• A pregnancy test (if you are premenopausal)
• Blood tests (for example, a complete blood count, iron levels, and thyroid hormones)
• An ultrasound of your pelvis

Your healthcare provider may also do a hysteroscopy, a diagnostic procedure used to visualize the inside of your uterus. They may also do an endometrial biopsy to sample your uterine tissue for microscopic examination.

Summary

Heavy menstrual bleeding is also called menorrhagia. If you bleed for seven or more days, need to change your pad or tampon every hour, or are producing large blood clots, you may be experiencing heavy menstrual bleeding.

Heavy menstrual bleeding can have a number of possible causes, including problems with the ovaries, uterine fibroids, pelvic inflammatory disease, and others. Certain medications may also cause you to bleed more heavily than usual.

If you experience heavy menstrual bleeding, it is important to see your healthcare provider for a diagnosis.