Let's start with the very basics: Perimenopause is not premature ovarian failure or early menopause. It is the time leading up to menopause -- a transition period that can last for years.

It's part of the natural progression your body makes as it shifts from being fertile to infertile, as your ovarian hormones begin cycling down and your eggs being dwindling.

A quick snapshot of what happens: As you get older, your ovarian follicles are aging as well. They produce less and less estrogen and progesterone....and, in response to this, your pituitary gland secretes higher and higher levels of FSH (follicle stimulating hormone) and LH (luteinizing hormone). It's your body's attempt to get your ovaries working as they used to -- an effort to get your ovaries to continue developing follicles which, in turn produce estrogen...and then, after ovulation, progesterone. And, for a number of years, this actually works. The increased FSH and LH levels do keep the "ovary factory" running. But over time, the levels must continue increasing to get the job done  -- and ultimately, the FSH and LH fail to kick off the production of enough estrogen and progesterone.

Usually, FSH levels begin rising about 5 years before actual menopause; and LH levels rise a bit later than this -- about 1 year prior to menopause. Estrogen levels begin declining, but often this occurs later in the continuum -- much closer to actual menopause.

Because of the shifts in hormone production, perimenopause is hallmarked by the emergence of symptoms -- changes in your period, hot flashes, mood swings....all those things that are often referred to as just plain menopause. Most women begin perimenopause in their 40s, but some women do begin noticing symptoms in their early 40s or even their late 30s. On average, perimenopause lasts about six years, but it can be as short as one year....or as long as ten or more. It's a very inexact thing to predict, frankly --  so it's one of those "there's no knowing how long it will last until you're through it" situations. Perimenopause is "officially" over when you have your last period -- and haven't had another in at least a year. At that point, you're considered to be post-menopausal and the transition is complete.

Unlike premature ovarian failure (POF) or early menopause (EM), when you're in perimenopause, you often ovulate and you still are producing hormones at higher than post-menopausal levels. In fact, most often, you'll be producing hormones in the normal range -- one of the reasons this can be a difficult condition to diagnose.

This is a crucial difference between perimenopause and POF or EM. And it's one of the reasons, if you're still in your late 30s and think it might just be perimenopause, to ascertain your hormone levels -- particularly your estradiol levels. (For more information on hormone levels, go to Hormone Tests) Most doctors concur that women with POF or EM should replace their hormones until the normal age of menopause, as there are numerous consequences for a woman faced with years of low estrogen. Perimenopause, on the other hand, isn't marked by these extremely low estrogen levels. Yes, your levels might be dropping....but they're still in what's considered the average range. This is why there's a distinctly different approach to coping with POF or EM on one hand, and with "normal" perimenopause on the other.

So how can you be sure if it's perimenopause?

It's the logical question -- but, unfortunately, it's not always an easy question to answer. As stated above, most women begin perimenopause in their mid 40s or later, but some do begin seeing symptoms in their late 30s or early 40s.

So age is probably the first tip-off. If you're younger than your late 30s, it's probably not perimenopause, but rather the beginning of POF or EM. (In this case, it's important that you see your doctor and ask for testing.) If you are in your late 30s or early 40s, then it could be peri...or it STILL could be POF or EM (it gets convoluted, no doubt about it!)

Usually, you get the indication that something is going on differently with your body when you notice changes in your period. This is one of the most common symptoms to appear. Sometimes, in the earliest stages of perimenopause, your cycle length shortens. In other words, your period comes more frequently -- every 25 days, say, instead of ever 28. You'll notice changes in your flow; often, your bleeding will be heavier; other times lighter. As time goes on and you get closer to menopause, your periods often become more irregular and you might even begin skipping periods from time to time. And, as menopause comes even closer, the frequency of skipped periods increases. About 75% of women will notice their cycle length slowly increase --  from the norm of 28 days to 60 days  -- usually in the last 5 years before menopause itself.

Then....your periods become less and less frequent, skipping periods becomes the norm, and you ultimately pass through menopause itself, the last period you'll have. (Note: In this case, you're not considered post-menopausal until one full year has passed since your last period.)

In addition to changes in your period, you might also notice other symptoms of hormone fluctuations -- such as hot flashes, night sweats, mood swings, change in weight distribution. Vaginal dryness often increases as a result of slowly dropping estrogen levels.

One key thing to remember: In perimenopause, your hormones are gradually dropping off, just as your ovarian function is gradually winding down. It's not a sudden shift in hormone levels, but a progression -- which is one of the main reasons that symptoms can vary greatly. Because hormone levels do bounce around quite a bit in perimenopause, it's not unusual to have these symptoms one month (or one day!) and feel perfectly fine the next. (It usually is different with POF or EM. In these cases, typically your symptoms remain more stable.)  It's also important to keep in mind that your body type can have an effect on the severity of your symptoms.  Heavier women tend to have fewer symptoms (as fat cells can both store and produce estrogen) while thinner women tend to have more and stronger symptoms.

If you're in your late 30s or early 40s and begin noticing symptoms arise, you might want to ask your doctor to test your hormone levels -- particularly your FSH (follicle stimulating hormone) levels. As your ovarian function starts to wind down, your FSH levels usually start to rise. This is especially important if you've begun skipping periods, as there is a chance that what you're experiencing isn't plain old perimenopause, but rather the onset of premature ovarian failure or early menopause.

Problem is, since in peri, your hormones can fluctuate a great deal  so there's a chance that when you get your blood drawn for a hormone test, your levels will appear completely normal even though you certainly don't feel normal. So some doctors might slough off your complaints, since they're not corroborated by your test results.

In this case, you have a few options. You might want to consider getting your FSH tested again, at least a month later. This is especially recommended if you have actually begun to skip periods.

In addition, many doctors feel it best to not go by an FSH test alone, but also think testing other hormone levels (particularly estradiol) can give a better picture of whether or not you're dealing with perimenopause or with POF.   One important note:  While some women may begin noticing symptoms of perimenopause as early as their late 30s, it's not terribly common to have low estrogen levels at this point...since low estrogen tends to occur very closely to actual menopause.   It's also wise to get your thyroid levels tested, as the symptoms of thyroid disease overlap with those of menopause. (There's more information about hormone testing under Hormone Tests.)

If you do get tested and learn that your levels are either normal (and you're still getting symptoms) or not at post-menopausal levels, but getting closer, then chances are that you're in perimenopause. If you learn that your levels at are post-menopausal levels, then -- again -- it's wise to get re-tested at least once more -- at least one month later (on cycle day 3 if you're still bleeding), to determine whether you're dealing with POF or EM instead.

How to Deal with Perimenopause

Because perimenopause is a natural transition -- something that is "normal" for lack of a better term, there's quite a bit of latitude in terms of treatment options....and quite a bit of debate!

The key with treating perimenopausal symptoms is focused on maintaining quality of life, not replacing hormones to forestall problems women with POF or EM face due to extended exposure to low estrogen. With peri, the issue is "how do you feel?" not "what will the consequences be?"

Along these lines, the main concern when it comes to coping with perimenopause is the severity of your symptoms. Many doctors prescribe low-dose birth control pills or, more recently, low-dose hormone replacement therapy.

• Low-dose birth control pills are probably the most common method of coping with perimenopausal symptoms. The pill suppresses the production of ovarian hormones and so regulates your period (which is typically very irregular at this point) in addition to preventing pregnancy. Today's low-dose oral contraceptives that combine estrogen and progestin prevent pregnancy and may mediate perimenopausal symptoms. Keep in mind, though, that use of birth control pills is generally not recommended for women with a history of blood clots, heart disease, hypertension, breast cancer or for those who smoke. In addition, because birth control pills supplant your own ovarian cycle with the schedule of the pill and also hides the symptoms of lower hormone levels, it's sometimes difficult to determine when you actually have gone through actual menopause. Remember, the estrogen in birth control pills is much more potent that that used in regular hormone replacement therapy --  so doctors advise that you go off birth control pills and either onto hormone replacement or no replacement as soon as possible. Generally, it's recommended that when you reach the average age of menopause (age 50 or so), you either simply switch off of birth control pills, or get your FSH levels taken (either on the placebo week of the pill or after taking a complete break from the pill for a while) to determine whether you are indeed menopausal at this point and whether it's time to go off the pill.

• Low-dose hormone replacement is another prescription method of dealing with perimenopausal symptoms. In this case, you're put on low doses of the HRT used for post-menopausal women. More and more hormones are now available in low doses (particularly since the Women's Health Initiative study) so there are numerous options. In this case, you're put on low doses to help mitigate the dropping levels in your own body thus helping ease the transition. The only problem with this? Because you are still producing ovarian hormones of your own and because you actually are sometimes producing NORMAL levels of these hormones, there's the chance of periodically getting a bit of an overload hormonally. On the other hand, however, low doses can help greatly with symptoms. Again, it's a matter of choice, personal preference, and your own specific situation.

• There are, of course, also are non-prescription ways of coping with symptoms. These allow you to deal directly with symptoms without changing the hormone balance in your body. Probably one of the best methods of symptom control is through phytoestrogens -- such as flaxseed, soy or red clover.   Phytoestrogens are very weak plant hormones that mimic (to a much lesser degree) the estrogen in the human body.  As such, they can minimize symptoms -- while doing other beneficial things, such as help lower cholesterol and more.  Other supplements like black cohosh and other herbs, and vitamins can help with specific symptoms. (see Natural Remedies and Vitamins for a more thorough discussion of the different options).  Keep in mind that -- as with anything -- while these options work well for some, they don't necessarily work for everyone.  So there's a bit of trial and error involved. 

• What about over-the-counter progesterone cream?   This is an area that has received heavy publicity.  Problem is, many of the claims which sound too good to be true are too good to be true.  A recent double-blind, controlled placebo study published in Menopause (the journal of the North American Menopause Society) found that progesterone cream that delievered 32 grams of progesterone a day worked no better than the placebo cream.  If you want to try progesterone cream, you're best off being sure you're getting a cream that delivers a higher amount -- typically one you'd get from a compounding pharmacy as opposed to over the counter

• Finally, there's also the "don't do anything" method of dealing with perimenopausal symptoms -- in truth, another good option! Cool showers, fans, and just bearing it and remembering this too shall pass...

Regardless of how you choose to handle your perimenopause, perhaps the best thing you can do is take this time to do a "lifestyle" check -- and make sure you're doing the most you can healthwise.  A good diet, exercise (weight-bearing exercise in particular to help keep your bones strong) and making choices such as quitting smoking can make a difference not only in terms of symptoms, but also for your overall health -- both during this transition and afterwards!