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1 in 3 American Women Experience Heavy Periods* Mirena is a hormone-releasing IUD that is FDA-approved to treat heavy periods for up to 5 years in women who choose an IUD for birth control.*Also known as heavy menstrual bleeding (HMB)

Normal vs heavy periods: what’s the difference?

If you experience heavy bleeding, you might think that’s just a typical part of having a period, but what you might not realize is that you could be experiencing heavy menstrual bleeding (HMB).


In order to understand exactly what HMB is, it helps to understand what a “normal” period is. Getting to know your cycle will help when it comes time to talk to your healthcare provider about your treatment options.



But what is a normal period, anyway?

Everyone is different, which can make it hard to know what “normal” even means. But there is an average, or range of typical characteristics. For example, a “normal” period (or menstrual flow) may:


  • Occur every 28 days on average

  • Last for about 4 to 5 days

  • Result in a total blood loss of about ⅐ cup



So what is heavy menstrual bleeding (HMB)?

According to its definition, women with HMB may lose ⅓ cup of blood or more during their period. Symptoms of HMB may include:


  • Needing to wear more than one pad at a time or having to use both a tampon and a pad
  • Needing to change pads or tampons during the night
  • Having menstrual periods lasting more than 7 days
  • Having a menstrual flow with blood clots the size of a quarter or larger
  • Having a menstrual flow that soaks through one or more pads or tampons every hour for several hours in a row


As one example, with heavy periods, you might soak through 1 or more pads or tampons every hour for several hours in a row.


A tampon filled with blood within an hour during a normal period
A tampon filled with blood within an hour during a heavy period

For illustrative purposes only.

1 in 3 American women experience HMB

Why do many women remain silent about their heavy periods?

One in 3 American women who have periods experience HMB, but it is known to be extensively underreported. Why is that? Because socially, periods are seen as taboo and there is a culture of silence surrounding them. Not only that, but for years women are told that their period symptoms—like heavy bleeding—are normal. This leaves many women putting up with HMB symptoms for years before realizing they can ask their doctor for help in finding a treatment option that might be right for them.

Downloadable HMB questionnaire about heavy periods

Prepare for a chat about heavy periods with your doctor

Use this list of questions to help with your conversation about heavy periods at your next appointment.

Download HMB Questionnaire
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Learn about a treatment option

Even though it’s common, you may not have to deal with heavy periods, so if any of this sounds familiar, it might be time to talk to your doctor. 

Learn More About Mirena


Mirena® (levonorgestrel-releasing intrauterine system) is a hormone-releasing IUD that prevents pregnancy for up to 8 years. Mirena also treats heavy periods for up to 5 years in women who choose intrauterine contraception.



  • If you have a pelvic or genital infection, get infections easily, or have certain cancers, don't use Mirena. Less than 1% of users get a serious pelvic infection called pelvic inflammatory disease (PID).
  • If you have persistent pelvic or stomach pain, or excessive bleeding after placement, tell your healthcare provider (HCP). If Mirena comes out, call your HCP and avoid intercourse or use non-hormonal back-up birth control (such as condoms or spermicide). Mirena may go into or through the wall of the uterus and cause other problems.
  • Pregnancy while using Mirena is uncommon but can be life threatening and may result in loss of pregnancy or fertility.

  • Ovarian cysts may occur but usually disappear.
  • Bleeding and spotting may increase in the first 3 to 6 months and remain irregular. Periods over time usually become shorter, lighter, or may stop.


Mirena does not protect against HIV or STIs.


Only you and your HCP can decide if Mirena is right for you. Mirena is available by prescription only.


For important risk and use information about Mirena, please see Full Prescribing Information.