The link between them all is age: To put it as simply as possible, early or premature  menopause is typically used to mean menopause that comes well before the average age of normal menopause -- when you're still in your 20s, 30s, or early 40s. 

More technically, as used by many doctors and medical journals:  Early menopause refers to menopause -- i.e. total cessation of your periods for 12 months -- before the age of 45.  Premature menopause is menopause that occurs before age 40.   If premature menopause occurs naturally -- that is, if you haven't had surgery, radiation treatment or chemotherapy that led to menopause -- it is more commonly now referred to as premature ovarian failure (POF).  This sounds devastating, I know.  But basically, all it means is that your ovaries aren't working as they should.  They're shutting down years, even decades, before their time.

(As you'd expect, it's actually more technical than this...but this is the terminology you might run across.  And there is more information about the different aspects of what is commonly called Early Menopause in the Causes section of the site.)

But let's start at the very begininng....

What exactly is menopause itself?  To put it very simply, menopause is the stop (pause) of your periods (menses).  Your periods stop because your ovaries have run out of eggs, are no longer responding to your body's hormonal signals,  have been damaged or have been surgically removed. 

Before your periods stop, you go through a transition period called perimenopause. This can last on average from two to six years, although some women have it for a shorter amount of time, and others longer.  And once your periods have stopped for a year, you're considered as being in menopause.

The average age for women to have completed menopause is age 51 -- which means that most women go through this change between the ages of 47 and 53.  So if you go through menopause before this -- for whatever reason -- you're usually said to have experienced premature or early menopause. So (here we go again!) the key factor is age.  

The two key ways to determine whether or not you're actually menopausal are 1) the length of time without a period, and 2) a test of your follicle stimulating hormone (FSH) hormone levels.  (There is more information about this in "How Can I Be Sure....")  Generally, if you've skipped periods for 12 consecutive months (or six, depending upon your age and/or doctor), if you still have your ovaries, and if your hormone levels test at post-menopausal levels, you will probably be told you are experiencing early menopause, premature menopause, or premature ovarian failure.

Here is a brief look at some of the different specific conditions that are often grouped together under the umbrella term "early menopause" in an attempt to help clarify things.

• PREMATURE OVARIAN FAILURE  (see POF Fact Sheet for more information)

Premature ovarian failure (POF) used to be commonly referred to as premature menopause -- as it is a condition in which your periods stop before the age of 40.  In this case, you usually have menopausal symptoms -- including a stop in your periods.  Most importantly, when you get a hormone test (a test of your follicle stimulating hormone, or FSH, and estradiol, the main circulating estrogen), you will test at post-menopausal levels.

Unlike "normal" menopause, however, premature ovarian failure (POF) doesn't necessarily mean that your ovaries are out of eggs.   Yes, sometimes this is the case  -- and then it is, perhaps rightly, referred to as premature menopause.  But sometimes you stop having periods not because you no longer have eggs, but because your body isn't responding to the signals to ovulate. 

You may produce enough estrogen on your own to get periods on occasion -- even after having been tested at post-menopausal levels.   (For example, my FSH level was at 156 -- definitely in the post-menopausal zone, yet I was getting periods.)  This isn't uncommon, and is one of the main differences between "normal" menopause and POF.

Moreover, you may not only get periods, but may also ovulate.  Studies have found that up to roughly 25% of women with POF do still have viable follicles and ovulate from time to time -- and 8 to 10% of women with POF actually get pregnant.  (This is a decisive difference between POF and regular menopause -- as once an older woman has gone through menopause, there is no chance of pregnancy at all, as there is no ovulation.)

• EARLY MENOPAUSE CAUSED BY SURGERY OR CANCER TREATMENTS

Sometimes, early menopause is a result of surgery or cancer treatments.  In this case, there's a clear outside cause for the change in your body.  

In the case of surgery:  If you've undergone an oophorectomy, your ovaries have been removed -- so you're no longer producing ovarian hormones.  Or you may have had another form of pelvic surgery (such as a hysterectomy) that interfered with blood flow to the ovaries and, over time, caused ovarian failure. In the case of cancer treatments, either chemo or radiation, the treatments have caused your ovaries to fail -- and, again, they're no longer producing the hormones they used to.

• PERIMENOPAUSE (see Perimenopause Fact Sheet for more information)

If you experience menopausal symptoms at an earlier than normal age, but are still ovulating and have your hormone levels tested at normal levels, you'll sometimes be told you're in early menopause.  However, it's probable that what you're actually experiencing is perimenopause. 

So what is perimenopause? This is the time leading up to full-blown menopause.  When you're in perimenopause, your hormone levels are fluctuating.  You're usually still ovulating (although you many begin having anovulatory periods)   Often if you get blood tests of your hormones in this period, you'll be told all is well....but you STILL feel rotten!

In fact, often when people talk about menopause, they're really talking about perimenopause -- since this is the time when you'll first begin noticing hot flashes, night sweats, changes in your period, mood swings, and the like.

It's not uncommon for women to begin perimenopause in their 40s -- although some will begin noticing perimenopausal symptoms (hot flashes, changes in their period, etc.) as early as their late 30s.  Many people refer to this early menopause, since the symptoms begin before the "expected" time.

Depending upon your symptoms, your doctor may recommend going on low-dose birth control pills or even low-dose HRT.  Unlike women with POF or EM, usually this is intended to mediate symptoms, not as literal hormone replacement to stave off the consequences of low estrogen at an earlier than usual age.

• DIMINISHED OVARIAN RESERVE

This is yet another instance where you're often still getting fairly regular periods -- and your hormone levels aren't testing at post-menopausal levels, but you're getting symptoms.

When this occurs before the age of 40, it's often viewed as a precursor to premature ovarian failure and is referred to as diminished ovarian reserve. 

Okay -- so that's a brief explanation of a very complicated topic!   The bottom line? Whatever the technical term that's used and whatever the cause, early menopause means one simple thing: your reproductive system is no longer working the way it used to.....and it's happening at an age when you didn't expect it to be happening.

You will need to get the proper testing from your doctor to be sure what is going on with your body -- and you should discuss the different options open to you regarding hormone replacement, health consequences and so forth.

Finally, it's important to remember that being told you are in early menopause, that you have premature ovarian failure, that you need to undergo surgical menopause, or whatever you're told, doesn't mean that you're automatically older.  It doesn't mean you're less of a woman, less desirable, or somehow diminished.  You're still you -- a young woman...with capabilities, dreams, and strengths.  The only thing that has changed is your reproductive system -- and you're much more than that!