What Are the Common Causes of Irregular Menstruation?

Mary McMahon
Mary McMahon

Common causes of irregular menstruation include disease, hormone imbalances, stress, and weight changes. It is important to be aware that the regular menstrual cycle can be quite variable; women may have between 11 and 15 periods a year, and some women naturally fall outside even this broad range. In the first few years after the onset of menarche, it often takes time for the hormones to get in balance, and irregular menstruation is very common. Patients who experience extreme cramping, very heavy bleeding, and other symptoms have a cause for concern, but the occasional out-of-synch period is not necessarily an indicator of a issue.

Some diseases, including diabetes, can lead to irregular menstruation.
Some diseases, including diabetes, can lead to irregular menstruation.

Many things can cause hormone imbalances, including the onset of puberty and the start of menopause. Younger and older women often have irregular periods as a result. In women of reproductive age, one of the most common reasons to have a hormone imbalance is pregnancy or breastfeeding. Missed periods can indicate the start of a pregnancy. Women who breastfeed their children may notice that they do not have menstrual periods while breastfeeding, although this is not the case for all women. Underlying disease can also be a cause of imbalanced hormones.

A woman with irregular menstrual cycles should consult her gynecologist.
A woman with irregular menstrual cycles should consult her gynecologist.

Diseases that can lead to irregular menstruation include polycystic ovary disease, endometrial hyperplasia, diabetes, and some cancers. If a patient is in treatment for a medical condition, she may want to discuss the impact it could have on her menstrual cycle. If irregular periods onset suddenly and are accompanied by other symptoms, this may be a sign of an emerging medical problem.

Abnormal menstrual bleeding can include getting menstrual periods too often or sooner than 21 days.
Abnormal menstrual bleeding can include getting menstrual periods too often or sooner than 21 days.

Stress, including emotional stress, travel, and physical stress from a heavy exercise regimen, can also cause irregular menstruation. Women may also menstruate irregularly when they gain or lose weight, especially if it happens rapidly. Nutrition can be a factor as well. Eating disorders like anorexia are often accompanied by irregular or absent periods because patients do not get sufficient nutrition and lose weight very quickly.

Extreme cramping and heavy bleeding during irregular menstruation may be a sign of a more serious problem.
Extreme cramping and heavy bleeding during irregular menstruation may be a sign of a more serious problem.

Patients who notice irregular menstruation can discuss them with a gynecologist. It is advisable to bring up any recent lifestyle changes and to provide a detailed history. The doctor can evaluate the patient for common risk factors and may run a few tests to check for obvious causes like an endocrine problem. Some women naturally have irregular periods, and if they become a problem, the doctor could recommend the use of hormone therapy to regulate menstruation. This can limit cramping and heavy bleeding and should make things more comfortable.

Excessive exercise may cause an irregular menstrual period.
Excessive exercise may cause an irregular menstrual period.
An woman with an eating disorder may experience irregular menstruation.
An woman with an eating disorder may experience irregular menstruation.
Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a wiseGEEK researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

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Discussion Comments


I want to have a baby but my menstruation is not regular.


It's been two years since I've had a period. The doctor has had me on the pill since I was in secondary school. It comes only after the last pill, then the next month, nothing. The doctor told me that my hormones are imbalanced. I want to have a baby. Please help. What pills I can take so that my periods can get back on track?


I am a 36 year old mother. My periods have always been very regular, right on 28 days with about one time per year an extra period at 14 days. I have an 11 year old daughter who has not yet started her period but has had all of the other signs of puberty for about 1.5 years. I have not had a regular period in three months! I have been getting it about every 20 - 23 days. Could the hormones raging inside my daughter be affecting my cycle? I feel like I am constantly on my period and cannot seem to pose the question right online to find an answer!


My friend Caroline is a 28 year old woman with a three year old baby. About a year after her delivery (it was c-section), she had a loop. Her menstrual cycles were all normal, but after she stopped breast feeding she started experiencing irregular periods. Thinking that it was the loop that was giving her trouble, she had it removed after consulting a gynecologist. Since then she has not had her periods at all and that was four months ago. She is still not pregnant. She is really concerned. Can there be any serious trouble?


I had my daughter seven months ago and started my period for two cycles and then randomly stopped, I am now a month and a half late and all pregnancy tests come up negative.

When my daughter was born I didn't feel a bond at all, but all of a sudden, I feel really close to her and that mother and daughter bond gets stronger every day and I feel more connected to her. I didn't breast feed her for long.

Is it possible that I started my period and now that I'm bonding with her maybe my body produced a hormone to make me quit having my period? I don't think I'm pregnant. I'm just trying to figure out what my body is doing and to see if it's worth going to the doctor for.


I have had a light menstrual cycle for eight days now. I'm used to three days with the contraceptive I'm using, however I messed up on my schedule, and I stopped taking it altogether.

I'm worried about my cycle right now, but there may be other factors contributing to my cycle behaving this way. I have recently been laid off, ended a relationship and stopped taking my birth control. I'm also naturally paranoid, which I'm sure is not helping the situation at all.

I want to get a pap smear done, however I'm not sure if I can, considering that I am menstruating at the moment. Any suggestions?


When I was a teenager I went through a hardcore dieting stage and it really wrecked havoc with my menstruation. I was actually lucky when my started out as it was quite regular, but with a poor diet and not enough calories my period became very irregular and eventually stopped all together.

If you feel the need to diet do it sensibly because not enough nutrition can really have a negative impact on your menstruation cycle as well as your overall health. I was happy that when I returned to eating normally that my period came back and got back to a regular cycle.


Taking birth control pills and especially switching brands is quite a common cause of irregular menstruation, at least until your hormones balance out.

When I was younger my doctor gave me birth control pills to lesson the effects of severe period symptoms, and it also ended up regulating my periods. Unfortunately, I ended up having to switch to another brand for financial reasons and it completely threw my cycle off. It took me months to get thing back in order.

So, if you have just started taking birth control, or have just switched brands, there is a good chance your periods will be off kilter for a while.


@lighth0se33 - Yes, I have pain in my legs then, too! I wanted to know why, so I read up on it.

Turns out that menstrual leg pain is pretty common. It can be brought on by a mineral or vitamin deficiency or dehydration. Another possibility is that your legs and your uterus might share a pathway of nerves. If this is the case, then uterine contraction pain could bring about pain in your legs.

Another possibility is that you might have endometriosis, a condition in which uterine tissue grows at other places in the body. Lesions might be found in your pelvic cavity, your intestines, your appendix, your colon, or your bladder. Endometriosis causes pain in the pelvis as well as in the legs and lower back, plus it messes up your menstrual cycles.

One more possible cause for leg pain is dysmenorrhea. It is very common and affects around 75% of women. This condition causes labor-like cramp pains, heavy flow, vomiting, nausea, dizziness, diarrhea, backaches, headaches, and leg pain.


Has anyone ever experienced leg pain during their period? I have pretty intense aches in my thighs during that time of the month, and I know it must be associated with it, but I just don’t know how.


Very informative article! I now believe that stress caused my irregular menstruation.

My job weighed heavy on me. I bore the majority of the workload, and it seemed more got given to me to do every day. During this time, my periods became unbearable. I bled so much that I would have to change tampons every hour, and the cramping made it very hard to do any work whatsoever. I often had to go home and take pain pills that I have on hand for another condition.

When I left that job, my menstrual cycle seemed to lighten up a bit. Though I still have the usual unpleasant cramps, they are not nearly as horrible as they once were.


I had always gotten my period pretty regularly. I could predict the week when it would happen each month.

That is why I thought something must be wrong when I went three months without a period. I felt fine otherwise, and I really did not want my periods to return, but at the urging of family, I went to my doctor. It was some type of hormone imbalance. She gave me a pill to take, and the periods started right back up again.

I never want to have children, and I have often questioned the wisdom of making my periods start again. I knew that my body had to have been telling me something was wrong, though, because that's just not normal.


I just wanted to say that older women that have an irregular menstruation cycle should keep track of when they menstruate because if the flow is heavy and frequent they might want to have that checked out by a gynecologist.

My mother was experiencing very heavy periods even though she was experiencing menopause. She dismissed this as it being menstruation, but it was uterine cancer. Aside from the heavy bleeding she also had very strong stomach pain. When she finally went to the hospital because the pain was unbearable, they told us that she had cancer and we later found out that it was at stage four.

Please see a doctor if you notice something out of the ordinary because uterine cancer is treatable and women that seek help early enough when the cancer is in its early stages have a 96% survival rate.


I have an irregular period, and I’ve got to say that when it comes – it comes. It is absolutely horrible and really hurts, actually.

The worst that I’ve ever had, though, was after I had my children. I nursed both of them, and many people do not realize that it is not unusual for a nursing mother to not a have a period for months. Nursing even provides a certain amount of birth control!

But, after you’ve had a baby, and then gone literally half a year or more without a period, the thing is unstoppable. Mine lasted for over a week, and I actually had to call in to work because of the horrid cramps.


You know, the oddest thing in the world happens when my baby sister comes home from college. Now, I have three sisters (one older and two younger) and none of us live in the same house anymore. Two of us have very irregular menstrual cycles.

But when that baby comes home for a visit, if she has a period, we all start within days. It doesn’t matter if you just had one – this has even defied the pill!

Is it possible that different women living together or being with each other frequently can actually affect their menstrual cycles? Mine has always been irregular so it’s kind of nice to occasionally get set on her super regular, every 28 days schedule.


I have never had regular periods for as long as I can remember. I guess I started when I was 12 and now I’m 31. I went to the doctor many times after I entered college about the problem and was always told that stress was the culprit. (Before I left home, my parents were against me seeing a gynecologist.)

Come to find out, I had polycystic ovarian syndrome, which is a disorder that does not just affect your period. It also affects fertility, body hair, weight gain and acne. However, one of the key indicators that you have it is that your periods are actually very far apart and random.

It really has not been unusual for me to go as long 6 months without a period. Since I was trying to get pregnant for years when I was I was first diagnosed, going on the pill to 'fix' my irregular periods was senseless.


@KaBoom - Wow every 21 days?! I feel very sorry for your friend. I can barely deal with having mine every 28! Luckily I am fairly regular though.

Although there are many benign causes for irregular periods I think anyone who has them should definitely go get checked out. As the article said cancer can be one of the causes! Very scary.

I've also known some very athletic women who either don't get their periods or get them on a very irregular basis. I know these ladies are in tip top shape but not getting your period just doesn't seem healthy to me!


This article is definitely spot on about menstrual cycles being highly variable. Despite what we're all told as young ladies not everyone is going to have their period every 28 days. I have one friend who only gets her period once about every 40 days and another unfortunate friend who gets hers every 21 days!

I myself get very regular "periods" thanks to birth control pills. I used to have highly irregular periods and it just got too hard to predict so I chose to go on the pill. I've definitely never looked back from that decision!

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