Menopause, the permanent pause in your periods (menses), is one of those things that you are not sure has happened until after it's over. Like the first time you met your best friend: You probably had no idea that you'd become so close. You only realized how special that occasion really was when you were able to look back on it. Okay, maybe menopause is not a warmed-fuzzy-greeting-card occasion, but it is a passage worth noting.

Are you or are not you menopausal? You can answer that question only after the fact – after you've gone a year without your period. Many of the annoying symptoms assigned to menopause actually are much worse prior to menopause in the phase known as perimenopause. During perimenopause, you get both the annoying symptoms (hot flashes, irritability, mood swings, and so on) and your period.

Previewing perimenopause

For many women, perimenopause is a big case of déjà vu. Remember puberty (vaguely)? Remember the crying jags, the mood swings, and the “what's wrong with my skin!” traumas? Well, guess what? They're back. Once again your hormones are ready to wreak havoc on your body, your emotions, and your mental faculties. This time around, however, you're a bit wiser, you have experience dealing with change, and you realize that this too will pass.

Some gynecologists advise women who are still experiencing periods not to worry about “menopausal” symptoms. But you know that the symptoms folks often attribute to menopause are usually felt as intensely or more intensely during perimenopause. And perimenopause can last for ten years before a woman stops menstruating altogether and becomes truly menopausal.

Experiencing periodic periods

During perimenopause, things change. If you welcomed your period on the same day as the full moon for 20 years, you may wake up to find the planets suddenly out of alignment.

The hormonal shift is due to changes occurring in your ovaries. Your ovaries hold little oocytes (seeds), and each month, some of these seeds develop into follicles (little sacs that hold an egg). One or two lucky follicles mature and release an egg. That's when you ovulate. The oocytes in your ovaries are held together by a substance called stroma. The stroma produces testosterone, and the follicles produce estrogen. When you're very young, you have hundreds of thousands of these little seeds. As you age, you have fewer seeds and and more stroma. As the mix of seeds and stroma in your ovaries changes, so does hormone production. Your ovarians decrease their production of estrogen but continue to produce testosterone.

Sometimes you ovulate during your cycle; sometimes you do not. Sometimes the FSH just does not get the follicles producing estrogen right off the bat. Estrogen levels are low at the beginning of your cycle when they should be high. Your brain responds to this lack of get-up-and-go by sending another surge of FSH. Finally getting the message, your ovaries become a little frantic and go into double-time production of estrogen. Right at the time when you should be ovulating and producing progesterone, your ovaries are just kicking into gear developing a follicle. That means you will not ovulate when you usually do and your period will be late.

Your menstrual cycle is all messed up. Your estrogen shoots up, and then it drops down. You get hot flashes and maybe even heart palpitations (a racing heart) when estrogen plunges. But just when you're convinced that something is seriously wrong and you need to schedule a gynecologist's appointment, you get your period and everything returns to normal. You wonder why you were so worried and cancel the appointment (if you made one) until the next weird thing happens.

This is all perfectly fine (maybe not with you, but with Mother Nature) – it's all part of perimenopause.