By Dr. Michelle P. Warren
What is an irregular period? What causes irregular periods?
If you’ve experienced menstrual cycles where you bleed at unexpected times, seem to bleed too much or don't even bleed at all, don’t worry, you're not alone. You’re just going through something that is actually quite common, irregular periods. These occur in about thirty percent of women who are in their ‘reproductive years’. These are the years when women who are having menstrual periods are capable of becoming pregnant. You may recall being a young teenager (or maybe you are a young teenager) and noticing that your periods were irregular or seemed to take a while to settle into a ‘schedule’. That's because irregular periods are especially common at the time when menstruation begins in adolescence. A similar syndrome often occurs at the end of the reproductive years when women approach menopause — usually in the mid-to-late forties. Ironically, a menopausal woman can actually be experiencing periods much like those of her teenage daughter. All women, however, should keep in mind that menstrual cycles may vary normally. The time between bleeding can be as short as 25 days and as long as 42 days. Although an occasional cycle of this length shouldn’t be cause for worry, be aware that if cycles continue to be shorter than 25 days or longer than 42, days or are associated with other symptoms, such as pain or heavy bleeding, it's a good idea to consult a doctor. Don’t worry, though, if your cycle does not always last exactly 28 days. Just as most women’s bodies aren't proportioned to fit exactly into one dress size, very few women have menstrual cycles that last precisely 28 days. (You can use our online period tracker to keep track of your period and see for yourself how long your menstrual cycle is!)
What causes irregular periods? What about irregular periods and ovulation? Well, the most common reason that women skip periods is that their bodies have not ovulated during a cycle. Ovulation is the time when the ovary releases an egg. This occurs in the middle of a menstrual cycle. For a variety of reasons, ovulation can sometimes be delayed or even not happen at all. When this happens, your period may be very late or totally absent. To understand how this happens, you need to understand what your period is literally ‘made of’. When you have your period, what your body is doing is shedding the endometrium, which is the lining of the uterus. The endometrium builds up over the course of the menstrual cycle and receives the signal to shed itself when ovulation occurs and the egg is not fertilised. Heavy bleeding may result if ovulation happens late and more than the usual amount of lining has continued to grow. You may be wondering what keeps the lining from building up when ovulation does occur. The answer lies in a hormone called progesterone, which is made by the ovary. Progesterone acts to stop the growth of the endometrium. The ovary makes progesterone for 14 days, after which the endometrium is shed as a menstrual period. Bet you never realised just how much action goes on in your body in the course of a month!
If you want to get really technical about irregular periods and ovulation (so you can sound really smart when talking to your girlfriends) you can think about something called a proliferative pattern. This is what happens when your body does not make progesterone and the endometrium builds up so much that it finally outgrows its blood supply. The result is that you have the kind of period in which blood is shed in a disorderly, erratic pattern, and bleeding may last a long time. Although this happens to many women and is quite common, we don't really know what causes it. It’s possible that the reason is related to the kind of stress that comes from dieting, rigorous exercise or travel where the body clock is disrupted. Remember this very important point, however. Though there are many reasons that you can miss a period or experience erratic bleeding, it's crucial not to ignore the obvious — that you may be pregnant. If you have a period that's abnormal, make sure to ask yourself if this is a possibility.
Irregular periods are sometimes the result of a hormonal imbalance. How do you know if you have a hormonal imbalance? The best way, of course, is to be evaluated by your doctor. If you continue to have irregular periods for longer than three months, you should probably make an appointment with your GP. You may have one of two types of hormonal problems. The first type happens when you have too much of a certain kind of male hormone. This hormone usually comes from the ovary and occasionally comes from the adrenal gland, which sits in the kidney. Since men do not menstruate (wouldn’t it be sweet justice if they did?), too much of this hormone will obviously cause your periods to become irregular or even stop. The second type of hormonal problem occurs when your body literally gets its signals crossed in coordinating the menstrual cycle. This confusion takes place in the brain — where else? And again, if you want to be really brainy about what's going on in your body, think about this: there are three places inside of you where your hormones can be disrupted. These are the hypothalamus, the pituitary gland, (both in the brain) and the ovaries (you remember those, they’re in the lower abdomen.) What happens is that the hypothalamus sends signals to the pituitary gland, which in turn sends signals to the ovary. These signals are sent from the brain in very specific pulses every 60 to 90 minutes. Since you’re reading this on a computer, think of all the signals and connections that must be made just for you to reach this page. Have you ever had trouble logging on to the Internet? Well, things are just as complicated inside your body. So it’s not all that surprising that circuits misfire from time to time.
Hormonal problems sometimes come with symptoms that you may not be wild about. Some of these symptoms include acne and excessive hair growth in areas such as the face, chest, stomach and thighs. In cases where you’re receiving too much of the male hormone, you may find that your hair is thinning in a way that resembles male pattern baldness or that you may be gaining weight. And, as we’ve been discussing, hormonal problems are associated with lack of ovulation, which results in infertility. So aside from all the other discomforts of a hormonal imbalance, you may find yourself unable to get pregnant — though hormonal problems should certainly not be a reason to forgo birth control if you’re sexually active.
In many cases, irregular periods will warrant an ultrasound examination, which allows your doctor to take a look at your ovaries. It may be that your ovaries have a so-called ‘polycystic appearance’. This means that there are small cysts on your ovaries. Although the ovaries are generally enlarged under these conditions, the cysts do not cause pain and there is no need for surgery. There are things that can be done, however. Many doctors prescribe oral contraceptives (birth control pills) to regulate the periods or, in cases of excess hair growth or other symptoms related to hormonal imbalances, it can be helpful to take prescribed drugs containing progesterone.
You’re probably wondering how you, a full-fledged woman, could ever end up with too much of a male hormone. While no one really knows for sure, recent scientific work suggests that it’s due to increased amounts of insulin, which causes the ovaries to make more male hormones than they should. On rare occasions, a tumour growing in the ovary or adrenal gland can make male hormones — don’t worry, this doesn’t happen very often. Sometimes the adrenal gland may lack enzymes, which cause it to make more male hormone. Again, though, this is technical stuff. The bottom line is that experiencing irregular periods means the signals involved in coordinating the menstrual cycle have been disrupted. The good news is that there are new, promising medications out there that may be able to reverse this syndrome in some women.
There are a few other symptoms of hormonal imbalances that we haven’t yet touched on. One of those is the secretion of milk from the breasts. This can be alarming if you’re not lactating (breast feeding) but it's usually nothing to worry about. Occasionally the pituitary may develop a benign (harmless) tumour, and this can cause secretion of milk from the breasts. Also, if a woman has an eating disorder such as anorexia nervosa or is training very hard for an athletic event such as a marathon, the periods may become irregular or stop altogether. In serious cases (such as severe anorexia) the ovaries may also stop functioning and young women can develop early menopause. One symptom of menopause is hot flushes. If this begins happening to young women it is likely that the problem is diet and exercise related. In many cases, there’s an eating disorder going on. If menopause-like symptoms are happening to you or a friend and you think it might be related to an eating disorder, it is crucial to seek help. In addition to harming your body in other ways, eating disorders can cause the ovaries to shut down, which can lead to osteoporosis.
Of course, women approaching menopause will begin to ovulate less regularly and therefore experience irregular periods. Even menopausal women who are still menstruating may also have hot flushes. Women at this age also often have fibroids, which are benign tumours of the muscular wall of the uterus. Even when ovulation is normal, these fibroids may cause irregular and sometimes very heavy bleeding.
You probably thought you were asking a simple question when you inquired about what causes irregular periods. What you’ve just read is a lot of information to grasp all at once. Just remember that irregular periods are very common and generally easily treated. If you experience one from time to time, don't get upset. If you think you might be pregnant, take a home pregnancy test. If you’re not pregnant and the symptoms persist for more than a few months, see your doctor. Most of these problems reverse on their own. Just remember this very important point: even if you’re periods are not regular, you should always use contraception if you’re sexually active and do not wish to become pregnant. Having irregular periods does not necessarily mean you cannot conceive. Would you like to talk about your own experience with irregular periods? Visit the Always message boards. Don’t worry; there won't be a quiz.