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Heavy menstrual bleeding is excessive menstrual blood loss that interferes with a person’s quality of life
Different birth control methods may affect the heaviness of your period
Needing to change a pad or tampon every hour or two is considered heavy menstrual bleeding
Your period is the shedding of the endometrium (the lining of the uterus) that grows each cycle to support a potential pregnancy. The first day of your period is the first day of your menstrual cycle.
Your period can be an important indicator of your health. It’s important to know what’s “normal” or typical for you. That means how often your period happens, how light or heavy it is, and how long it lasts.
Changes to your period
Periods fluctuate for a while after they first start (menarche), after pregnancy, and as they come to an end (perimenopause). Not ovulating regularly — anovulation — is common during these times, and is a common cause of temporarily absent or heavy menstrual periods (1,2). If you don’t ovulate each cycle — you may miss a period, or it may come later than usual, and/or be heavier or lighter and/or shorter or longer than your usual period (1).
In between these life stages, your period should generally be about the same length and volume each cycle. You may still notice some changes though—the heaviness and length of your period depends on your hormones, which can fluctuate. Hormones can change temporarily because of things like stress, exercise, diet, or taking an emergency contraception pill (the morning-after pill) (3-6). Every period is different, just as every body is different.
Periods and uterine bleeding can also fluctuate because of certain health conditions, like uterine polyps, fibroids, or PCOS — conditions that should be addressed with your healthcare provider. Certain bleeding conditions, medications, and infections can also affect menstrual bleeding, and cause unpredictable spotting (7).
If you use hormonal contraception, your period/bleeding patterns may be different.
How much bleeding is considered heavy menstrual bleeding (HMB)?
Healthcare professionals and researchers have previously defined HMB as the loss of more than 80 mL of blood in one menstrual period (8). However, this is difficult to measure (9). Additionally, this definition didn’t take into account people’s perceptions and experiences, such as difficulties containing the blood flow (leaks), the impact on quality of life, or the impact of flow on daily living (2,10).
If you’re experiencing dizziness, fainting, lack energy, are short of breath, or your bleeding is so heavy that it keeps you from doing the things you normally do, such as going to work or school, then you may have heavy menstrual bleeding (11).
If you’re repeatedly soaking through a tampon or pad every one to two hours, this is considered heavy menstrual bleeding and should be brought to your healthcare provider’s attention (10).
What is the typical period volume for people not on hormonal birth control?
Adult period volume
A typical adult period usually lasts up to 8 days (12). Across the length of your period, it’s typical for between 5 to 80 ml (that’s up to 6 tablespoons) of menstrual fluid to leave your body (13).
The heaviest days of menstrual bleeding are usually at the beginning of the menstrual cycle (around the first and second day) (13). During the heaviest days of your menstrual cycle, you may notice clumps or clots in your menstrual fluid—this is common. If you have clots larger than about an inch or 25 mm long, it's a good idea to talk with your healthcare provider (11).
The color of your menstrual fluid may also change as you progress through your period, with bright red blood being more common as flow is heavy, and darker shades when your flow approaches the end of your period.
Adolescent period volume
The amount, length, and frequency of periods around the time of menarche can vary greatly. It’s common for cycles to be somewhat unpredictable for a few years after your first period. As you progress through adolescence, period amounts and cycles become more regular, but may still be somewhat variable (2,14).
Adolescent periods can also be up to 80 mL per period, like the adult range, but are often lighter (2).
What is the typical “period” volume for people on hormonal birth control (e.g., the pill, the ring, the patch)?
Hormonal birth control (HBC) options like the pill, vaginal ring, or patch control the release and regulation of hormones like estrogen and progesterone within your body. When used correctly, the hormones in HBC prevent your ovaries from preparing and releasing eggs (ovulation).
Your period will change depending on the type of HBC you use. Bleeding typically happens during your “no hormone” days (when you take placebo pills, or the times in between new rings or patches). The bleeding you experience while using hormonal birth control is called withdrawal bleeding, and is not considered a menstrual period. Withdrawal bleeding is caused by the decline in reproductive hormones in your body during days when you get low or no hormones from your pill, patch, or ring (13,15).
Many people experience lighter bleeding, and some don’t bleed at all while using hormonal birth control (16). When affected by hormonal birth control, the lining of your uterus doesn't thicken as much as it does without hormonal birth control. This typically results in lighter, shorter, or occasionally absent “periods”, especially for people who have been using hormonal birth control for many months or years.
What is a typical “period” volume for people on progestin-only birth control (e.g., the mini pill, the shot, the implant)?
There are many different types of hormonal birth control, all containing different types and levels of hormones. Some types of birth control do not contain any estrogens and only contain progestin—a synthetic form of progesterone (17). These methods include progestin-only pills (the mini pill), progestin injections (the shot), or progestin implants (17).
When using progestin-only birth control pills, you may not have a typical menstrual cycle. Some progestin-only pills suppress ovulation, but it depends on the type (17). Bleeding can vary a lot on progestin-only contraceptives. Changes in period amount happen in response to the changes in hormones. These hormones affect the growth and shedding of your uterine lining.
Many people experience unpredictable bleeding, reduced bleeding, shorter cycles, or amenorrhea (no menstrual period) with progestin-only pills, especially when pills are not taken at the same time every day (18).
The shot and the implant
Methods like the contraceptive injection and the implant suppress ovulation (19,20). Most people who don’t ovulate due to these progestin-only contraceptives experience shorter, lighter, or occasionally absent bleeding days, though this doesn’t always happen (17).
Unpredictable bleeding, spotting, and prolonged bleeding are common when using these methods, especially during the first few months (21). These symptoms usually improve with time, but they can continue for some people.
What’s a typical period amount for people with intrauterine devices (IUDs)?
The hormonal IUD
While using the hormonal IUD, it’s common to experience unpredictable bleeding or lighter bleeding, and some people don’t bleed at all (17,22,23). This happens because the endometrium doesn’t thicken as much as it does when you’re not using hormonal birth control. This typically results in lighter or occasionally absent bleeding, especially for people who have been using the hormonal IUD for many months or years (17).
The copper IUD
Copper IUDs are non-hormonal, so you will experience the same fluctuations of estrogen and progesterone across your cycle as you did when you weren’t using a copper IUD.
Many people experience an increased amount of menstrual flow and longer period length while using the copper IUD, especially in the first 6–12 months (17,24). This may happen due to vascular changes and changes to blood flow in the uterus (23,25-27). Bleeding may be accompanied by an increase in large clots and cramping.
Spotting is defined as any vaginal bloody vaginal discharge with a volume not large enough to require the use of period products (i.e., you don’t need to use a pad or a tampon) (13). Generally, if you have light bleeding that occurs at the beginning of your period, you should consider that part of your period, not spotting. However, if it’s very, very light—you only see a little on your toilet paper—that would be considered spotting.
Spotting can be caused by a variety of reasons, including hormonal birth control (HBC), ovulation, or other physiological reasons (3,16,28). If you experience spotting on a regular basis, talk to your healthcare provider as they may need to adjust your birth control (if you are using HBC) or investigate to find a cause. Spotting is common in the first weeks of pregnancy, and can also be caused by certain infections and physical changes, which should be addressed with a healthcare provider (7,29,30).
When should you seek help from your healthcare provider about your period heaviness?
You should speak to your healthcare provider if:
You have periods that last more than eight days
You need to change your tampon or pad more than every one or two hours
You need to double up on period products because of heavy bleeding (e.g., you have to wear a tampon and pad at the same time)
You have a menstrual flow with blood clots the size of a quarter/€1 coin (1 inch/25 mm) or larger
You have a menstrual flow so heavy that it keeps you from doing the things you would normally do, such as going to work or school
You’re dizzy, faint, lack energy, or are short of breath (10-12,14)
Excessive menstrual bleeding can impact a person’s quality of life and can cause anemia (31-33). Heavy menstrual bleeding can have many potential causes including: fibroids (growth of muscle tissue on your uterus), adenomyosis (a condition where endometrial tissue invades the muscular wall of the uterus), problems with blood clotting (like Thrombocytopenia or Von Willebrand disease), uterine polyps (growths on the inside of your uterus), and (rarely) tumors (34,35).
If your period has stopped and you are not taking any form of hormonal contraceptive, you should also discuss this with your healthcare provider.
Even if your period falls out of the “official” typical range, it’s important to know what is typical for you. The majority of health research is conducted on populations from Western industrialized countries, which may not reflect your own personal genetic background or environment. Everybody is different, just as everyone's period is different. Speak to your healthcare provider if you are concerned about your period volume.
Article was originally published 29 May 2018.