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As a menstruating woman, you may feel concerned when your period is off.
But before you get too alarmed, know that “abnormal” menstruation is not that uncommon. In fact, up to one-third of women have abnormal menstruation at some point in their lives.
However, the exact prevalence of these abnormalities may vary depending on several factors such as your location, lifestyle, occupation, and so on. One study estimates that the range of women who experience abnormal menstruation is anywhere between 5% to 35.6%.
So what exactly is abnormal menstruation anyway, and what should you do if you have irregular periods?
Keep reading to learn all about the 8 types of abnormal menstruation, plus when to seek support!
Takeaways
- While abnormal menstruation (aka abnormal uterine bleeding) may feel concerning, it’s not actually that “abnormal.” Around 1 in 3 women experience menstrual irregularities at some point in their lives.
- Abnormal menstrual bleeding is when you have irregular patterns with your period. This can include the length of your bleed, the amount of blood lost, cycle length, and pain levels.
- The 8 types of abnormal menstruation include:
- Amenorrhea: not having periods for more than 3 months
- Oligomenorrhea: cycles longer than 35 days or less than 9 periods per year
- Dysmenorrhea: painful periods
- Menorrhagia: menstrual bleeding that is heavy or longer than normal
- Hypermenorrhea: same as menorrhagia
- Metrorrhagia: bleeding between periods
- Polymenorrhea: periods with less than 21 days in between
- Hypomenorrhea: menstrual bleeding that is very light and less than 2 days in duration
- For an official diagnosis, you’ll need to have a solid understanding of your unique cycle patterns and consult with a doctor.
- Abnormal uterine bleeding here and there can be normal. But if you experience abnormal menstruation in 3 or more cycles a year, it’s best to see a physician.
- Keeping tabs on the patterns of your unique period can be very helpful. It’s especially helpful to keep track of your typical symptoms and when you begin and end menstruation.
What is abnormal menstruation?
Abnormal menstruation is also sometimes also called abnormal uterine bleeding (AUB). Whatever you call it, it means that there’s some sort of irregularity with your menstrual period.
To put this into perspective, let’s see what’s considered a “normal” menstrual cycle.
A normal menstrual cycle has the following characteristics:
Characteristic | What it means | What’s “normal” |
Cycle length | Measured from day 1 of your period to the last day before your next period | 21 – 35 days |
Length of bleed | How many days you experience bleeding | 2 – 8 days |
Flow of bleed | The average amount of blood lost in a given cycle | ~30 mL (above 80 mL = abnormal) |
Presence of other symptoms | Symptoms could include abdominal cramping, mood swings, etc. | Symptoms are mild (i.e. they may be uncomfortable but not severe or debilitating) |
If your menstrual cycle falls outside of these typical parameters, it’s possible you have abnormal menstruation.
Knowing these general standards is helpful because your menstruation—regular or irregular—gives insights into your overall health.
This is just a starting point for identifying irregular menstruation though. Keep reading to further understand all 8 types of abnormal menstruation.
What are the 8 types of abnormal menstruation?
Here’s a quick look at the specific types of irregular menstruation and how common they are:
Irregularity | What it means | How common it is |
Amenorrhea | Absence of periods (no period for more than 3 months) | 25% of women |
Oligomenorrhea | Long menstrual cycles (less than 9 per year or longer than 35 days) | 13.5% of women |
Dysmenorrhea | Painful periods | 50% of women |
Menorrhagia | Heavy or unusually long bleeding | 1 in 5 American women |
Hypermenorrhea | Bleeding that’s unusually long or heavy (interchangeable with menorrhagia) | Same as menorrhagia |
Metrorrhagia | Intermenstrual bleeding | 25% of women |
Polymenorrhea | Periods that are more frequent (less than 21 days apart) | Between 3% and 34% of women |
Hypomenorrhia | Lighter than normal bleeding (usually less than 2 days) | More research needed for a better estimate |
Wondering more about a particular irregularity?
See below for an up-close look at each type of abnormal menstruation, its cause, and how you can diagnose it.
1. Amenorrhea
The prefix a means “without” or “absence.” And menorrhea means period or menstrual flow. So amenorrhea is when you don’t have periods.
(Note: This doesn’t include times when it’s normal to not have a period. Like pregnancy, menopause, or breastfeeding).
There are mainly two types of amenorrhea: primary and secondary. Primary amenorrhea refers to when a young woman has not yet had her first period by the age of 15.
Secondary amenorrhea is when a menstruating woman stops getting her period for 3 or more months.
Prevalence of amenorrhea:
About 1 in every 25 women will experience amenorrhea at some point in their lifetime.
Causes of amenorrhea:
- Birth control
- Eating disorders
- Stress or excessive exercise
- Polycystic ovary syndrome (PCOS)
- Thyroid issues
- Pituitary gland tumors
- Genetic and chromosomal abnormalities (like Turner’s syndrome) can cause primary amenorrhea
How is amenorrhea diagnosed?
Not noticing a period after 3 months or longer.
2. Oligomenorrhea
Oligo is a prefix that means “little” or “few.” So, oligomenorrhea refers to when you have fewer periods than most women. This means that the length between your periods is irregular (more than 35 days apart).
Prevalence of oligomenorrhea:
About 13.5% of menstruating women experience oligomenorrhea at some point. But that rate can go up to as high as 44% for dancers or 60% for athletes.
Causes of oligomenorrhea:
- Polycystic ovary syndrome (PCOS)
- Hyperthyroidism
- Eating disorders
- Overexercising
- Birth control
- Primary ovarian insufficiency (POI)
- Menarche
- Perimenopause
How is oligomenorrhea diagnosed?
When you have less than 9 menstrual cycles in the span of a year. Or if you have menstrual cycles that are consistently longer than 35 days.
Know more: Why Is My Menstrual Cycle Getting Longer?
3. Dysmenorrhea
Dys is a prefix that means “difficult” or “bad.” So dysmenorrhea refers to menstrual periods that are painful.
There are two types of dysmenorrhea: primary and secondary.
Primary dysmenorrhea is technically “normal.” This is when you experience mild or moderate pain during your period. In this case, the sensation of pain that you feel is due to prostaglandins.
Prostaglandins are natural chemicals that cause your uterine blood vessels and muscles to contract. These contractions can cause cramping and abdominal discomfort.
When you begin a new menstrual cycle, you have a high amount of prostaglandins. This is why the first and second day of your period tend to be the most uncomfortable. A few days into your cycle, when most of your uterine lining has been shed, the level of prostaglandins decreases. And so does your pain.
Now, secondary dysmenorrhea is a little different. This is when you have an underlying disorder (either within the uterus or outside the uterus) that is causing you to have painful periods.
Prevalence of dysmenorrhea:
Over 50% of menstruating women experience period pain for a day or two each menstrual cycle.
Causes of dysmenorrhea:
As mentioned, primary dysmenorrhea is caused by higher levels of prostaglandins. But secondary dysmenorrhea can be caused by the following conditions:
- Endometriosis: Up to 29% of women who have dysmenorrhea also have endometriosis.
- Uterine fibroids: These are non-cancerous growths that grow from the muscle tissue inside of the uterus.
- Adenomyosis: This is when there’s abnormal growth of endometrial tissue inside the muscles of the uterus.
- Endometrial polyps: These are non-cancerous growths that grow on your uterine lining.
- Interstitial cystitis: This is when you have bladder pain or pressure.
- Pelvic inflammatory disease (PID): This is an infection inside of your fallopian tubes, ovaries, or uterus.
How is secondary dysmenorrhea diagnosed?
Diagnosis secondary dysmenorrhea is a little more subjective. But when you have period pain that affects your ability to function in regular daily activities, it’s a sign of an underlying condition. Sometimes, there are additional symptoms that may accompany the pain.
These include:
- Dyspareunia (painful sex)
- Menorrhagia (more on this next)
- Intermenstrual bleeding (bleeding between cycles)
- Postcoital bleeding (bleeding after sex)
One helpful way to keep tabs on the intensity of your period pain is to use an app like Inito. The Inito app allows you to track 20+ symptoms, including a special section dedicated just to abdominal pain.
Know more: Do Painful Periods Mean Good Fertility?
4. Menorrhagia and 5. Hypermenorrhea
The prefix meno means “menstrual blood.” And the prefix rrhagia means “profuse discharge” or “excessive flow.” So menorrhagia is when you have menstrual bleeding that is abnormally heavy or long.
Menorrhagia is also called hypermenorrhea, with hyper meaning “excessive” or “above normal.”
Note: We’re listing these two abnormalities together. Even though the terms are different, they both refer to heavy menstrual bleeding (HMB).
If untreated, the amount of blood loss you experience can interfere with your health and quality of life.
Prevalence of menorrhagia: 1 in 5 American women suffer from menorrhagia/hypermenorrhea
Causes of menorrhagia:
- Hormonal imbalances, such as PCOS (polycystic ovary syndrome) (when you have inconsistent periods, it could cause your periods to last much longer than what’s normal)
- Uterine fibroids or polyps
- Bleeding disorders
- Cancer of the uterus or cervix
- Using an intrauterine device (IUD)
- Miscarriage or ectopic pregnancy
- Medications such as blood thinners
How is menorrhagia diagnosed?
Any of the following could mean you have menorrhagia:
- Menstrual bleeding that lasts beyond 7-8 days
- Soaking through a pad, tampon, or menstrual cup every hour
- Having to double up on pads to contain your bleeding
- Having blood clots the size of a quarter or larger during your period
- Having to wake up at night to change your pad or tampon
- Experience extreme tiredness, lack of energy, or shortness of breath during your period
6. Metrorrhagia
The prefix metro means “uterus” or “womb,” and again, rrhagia means abnormal bleeding or excessive bleeding. So metrorrhagia is when you experience bleeding between your menstrual periods. This is also called intermenstrual bleeding.
This type of abnormal bleeding might happen at inconsistent intervals. And it’s not part of your typical period bleeding.
Prevalence of metrorrhagia: 1 in 4 women have intermenstrual bleeding at some point.
Causes of metrorrhagia:
- Menarche
- Perimenopause
- Birth control
- Anovulatory cycles (when you don’t ovulate)
- Underlying conditions like thyroid disease, endometriosis, PCOS, uterine fibroids
- Adenomyosis (when the inner lining of your uterus grows into the muscular lining)
- Sexually transmitted infections (STIs)
- Pelvic inflammatory disease (PID)
- Cancer (in rare cases)
How is metrorrhagia diagnosed?
When you notice bleeding or spotting that occurs outside of your menstrual period.
Keeping track of when you get your period each month is a helpful way to notice if you have intermenstrual bleeding. You can do this with Inito!
7. Polymenorrhea
The prefix poly means “many.” So polymenorrhea is when you have more menstrual periods in a single year than normal. This means that your periods are more frequent (usually less than 21 days apart).
Prevalence of polymenorrhea: In one study of women aged 13 – 21, 3% had current menstrual cycles lasting less than 21 days. But up to 34% of those women claimed to have experienced cycles less than 21 days at some point in the past.
And in a meta-analysis of menstrual disorders post-COVID, 16.2% of women had polymenorrhea.
Causes of polymenorrhea:
- High levels of stress
- Menarche
- Perimenopause
- Endometriosis
- A hyperactive pituitary gland
- Sexually transmitted infections (STIs)
How is polymenorrhea diagnosed?
When you have menstrual bleeding that occurs less than 21 days apart for more than 3 cycles.
8. Hypomenorrhea
The prefix hypo means “less” or “below.” So hypomenorrhea is when your period bleeding is very light and lasts less than 2 days in duration.
Prevalence of hypomenorrhea: Studies up to this point have differing standards for what’s considered hypomenorrhea. So it’s hard to state a precise prevalence for now.
Causes of hypomenorrhea:
- Menarche
- Low body weight
- Perimenopause
- High levels of stress
- Birth control
- Overactive thyroid gland
How is hypomenorrhea diagnosed?
When you have periods that are less than 2 days long or if you have very light spotting or bleeding instead of true period bleeding.
While it can be helpful to understand all of these menstrual abnormalities, this may feel like a lot of information to soak in all at once.
Here’s the bottom line: Pay careful attention to your unique menstrual period patterns. That way, you will be more empowered to notice any abnormalities and seek medical support if necessary.
And for a simplified summary of when to seek medical attention, head to the next section!
When to see a doctor about abnormal menstruation?
If you have an occasional menstrual irregularity, it’s not necessarily an immediate cause for concern!
Having inconsistencies with your period a couple times each year can be normal. Sometimes making changes to your diet, exercise routine, or sleep schedule can impact your hormones and as a result, your period.
That said, if you have recurring issues with your period (irregularities in more than 3 cycles a year), it’s best to see a doctor. They can help you more carefully diagnose what’s going on through testing, getting a medical history, and doing a physical exam. From there, they can give you an official diagnosis and suggest a treatment plan if needed.
But even before seeing a doctor, trust yourself if you feel that something about your period isn’t quite right. It’s always best to err on the side of caution.
Inito can be a great tool for tracking and confirming ovulation, and keeping a tab on your symptoms. This is because, on top of helping you track symptoms like pain and menstrual flow, Inito also helps you predict and confirm ovulation by measuring four key fertility hormones in your urine.
Having this comprehensive picture of your cycle is incredibly useful for discussing menstrual patterns with your doctor. At the end of the day, a healthcare provider is super knowledgeable about menstruation in general. But you are the one who knows your unique cycle the best!
FAQs
It’s possible that your menstrual cycle is on the shorter side. Normal menstrual cycles can range from 21 to 35 days long. Another possibility is that you may be experiencing intermenstrual bleeding (aka metrorrhagia).
An occasional missed period can be normal. But if it happens more frequently (like 3 or more times in one year), consult with your doctor. It could be a sign of an underlying health condition.
Not directly. The underlying infection you’re treating could make your period late (due to inflammation and added stress on your body), but not the antibiotics themselves. The exception to this is an antibiotic called rifampin which is used for treating tuberculosis.
Know more: Can Antibiotics Make Your Period Late? Know the Truth
There are several different types of irregular bleeding:
- Prolonged bleeding that lasts more than 8 days
- Heavy bleeding that soaks through a pad or tampon in an hour
- Menstruation that includes blood clots around the size of a quarter or bigger
- Bleeding between menstrual periods
- Menstrual bleeding that only lasts for two days or less
- Bleeding less than 21 days or more than 35 days apart for more than 3 cycles
Normal menstrual periods last between 2 – 8 days. So any period that is shorter or longer than that could be considered irregular.
If you’re worried you have irregular periods, schedule an appointment with your healthcare provider. They can run some diagnostic tests and check in with you about your observations and medical history to help determine the root cause.
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- Abnormal Uterine Bleeding – StatPearls – NCBI Bookshelf
- The Impact of Irregular Menstruation on Health: A Review of the Literature – PMC
- The Normal Menstrual Cycle and the Control of Ovulation – Endotext – NCBI Bookshelf
- Amenorrhea: Absence of Periods | ACOG
- Oligomenorrhea – StatPearls – NCBI Bookshelf
- Dysmenorrhea: Painful Periods | ACOG
- Dysmenorrhea – StatPearls – NCBI Bookshelf
- About Heavy Menstrual Bleeding | Bleeding Disorders in Women | CDC
- Intermenstrual and post-coital bleeding – ScienceDirect
- Covid-19 vaccination and menstrual disorders among women – Science Direct
- COVID-19 vaccination and menstrual disorders among women: Findings from a meta-analysis study – ScienceDirect
- Menstrual patterns and menstrual disorders among adolescents – PubMed
