Perimenopause vs. Menopause: What’s the Difference?

As you get older, your life changes. Sometimes quickly, sometimes slowly. Sometimes personally, professionally, or privately. And, eventually, biologically. 

Perimenopause and menopause are some of the most profound biological changes your body goes through as time passes, bringing you from your reproductive years (if you choose to use them that way) into the next phase of your life.

But what’s the difference between perimenopause vs. menopause? When does one become the other, and at what moment are we in perimenopause vs. menopause? The answers might not be quite what you think.

Here’s the lowdown on what perimenopause and menopause are, when you might start experiencing symptoms and what those symptoms might be, plus how to tell whether you’re in perimenopause vs. menopause.

What are the different biological phases?

The best way to understand differences between perimenopause vs. menopause is to learn about the biological phases that happen leading up to and during each shift. Here’s the timeline.

What is premenopause?

Before we jump into the midlife changes, let’s rewind briefly to understand the basics.

After your first period (or “menarche,” as it’s termed medically), you start ovulating. Not right away, of course — depending on your age when your periods start, it can take anywhere from five to ten years before you ovulate regularly. Once things get going, menstrual cycles and ovulation become more regular for many people.

During ovulation, an egg is released from your ovaries. That egg can then be fertilized by sperm if you have sex (or conceive medically) around the time of ovulation, meaning if you ovulate, your body is able to get pregnant.

At this point, you’re in what’s called “premenopause,” or your reproductive years. Premenopause is the stage of life stretching from when you’re able to get pregnant all the way up to when you start experiencing the symptoms and hormonal changes of perimenopause. In other words, a really long time—decades, for many.

Keep in mind that referring to this portion of your life as “reproductive years” is simply one biological way of marking the time before your body transitions to the next stage. How you spend this time is, of course, up to you—there are many other ways to define these years of your life outside of having children.

What is perimenopause?

After premenopause comes perimenopause. 

Literally, “perimenopause” means “around menopause.” This is the time when your body begins transitioning away from your reproductive years and towards menopause. Perimenopause is also helpfully referred to as the “menopausal transition.”

Perimenopause usually begins in your late 30s or early 40s, although this can vary from person to person. While the duration is also unique to each individual, perimenopause can last anywhere from a couple of years to over a decade, and generally lasts about seven years.

As you go through perimenopause, your body begins experiencing biological shifts. These shifts are largely driven by hormonal changes, namely to reproductive hormones like estrogen and progesterone. 

More specifically, your body’s reproductive hormone production decreases during perimenopause. As these hormone levels decline, they also fluctuate significantly—and irregularly—from cycle to cycle. 

Fluctuating and declining hormone levels can lead to any number of physical and emotional symptoms, beginning during perimenopause and continuing into menopause. Hot flashes and changes to your menstrual cycle are the most common initial signs that you’ve entered perimenopause.

>>MORE: Why Do I Have Horrible Perimenopause Symptoms? (Plus, 30+ Ways to Find Relief)

During perimenopause, your cycles may lengthen and you may go longer stretches of time without a period. In fact, it’s common for your period to skip a month, or several, and then come again. By late perimenopause, you may even go 60 days or more between periods.

Perimenopause lasts until the transition into menopause is completed. Symptoms may worsen as you get closer to menopause. As long as you have at least one period in a 12-month span of time, you’re still in perimenopause and you haven’t yet reached menopause.

What is menopause?

Menopause follows perimenopause. 

Menopause is your last menstrual period. When you reach menopause, your menstrual cycles and reproductive years come to an end.

How do you know if you’ve had your final period and gotten to menopause? Well, it’s a waiting game: you have to wait a year to see if you get another period. 

Once you’ve gone 12 consecutive months without a period, you officially hit menopause. (If you get another period during this time, even after a long wait, you’re still in perimenopause.) This means that menopause is confirmed after the fact – 12 months after, to be exact.

For many people, menopause occurs sometime in their 40s or 50s. The average age of menopause in the U.S. is 51. 

The reproductive hormone levels that started declining during perimenopause reach their lowest point with menopause. 

Take estrogen, for example. The ovaries are the main source of estrogen during your reproductive years. At menopause, your ovaries stop making estrogen altogether – meaning body-produced estrogen is extremely low at this stage.

Around the time of menopause, many people continue to experience the physical and emotional symptoms that first began during perimenopause. There are, however, a few key differences: for instance, your menstrual cycles are no longer irregular—they’re over. 

What is medical menopause?

Menopause can also be medically induced. In most instances, this is done out of medical necessity, like for cancer treatment, rather than through elective procedures. 

Medical menopause can be triggered by:

• Surgery to remove the ovaries (oophorectomy) or the uterus (hysterectomy)
• Medical treatments, like chemotherapy or radiation
• Hormone therapy, such as ovarian suppression therapy

When menopause is induced medically, it comes on suddenly. Depending on where in the reproductive or transitional years you are, perimenopause may be drastically shortened or you may skip over it entirely and go straight into menopause. 

Symptoms of medical menopause are often more intense than symptoms you may experience if you go through natural menopause (when your body transitions out of the reproductive years on its own).

In some cases, medical menopause may be reversible, meaning your ovaries eventually resume normal function and fertility is restored. However, this depends on your age, health, and the type and duration of treatment, among other factors, and is not the case for everyone who experiences medically-induced menopause. 

Natural menopause, on the other hand, marks the permanent end of your reproductive years – an end that begins during perimenopause.

What is postmenopause?

Menopause, diagnosed retroactively, is really only a moment in time.

Once you’ve gone 12 consecutive months without bleeding (meaning you’re 1 year out from your final menstrual period and official menopause has just been diagnosed), you’re in postmenopause. 

During postmenopause, you may continue to experience perimenopausal and menopausal symptoms for some time. Low reproductive hormone levels are still the culprit behind postmenopause symptoms.

For some people, however, symptoms may get milder or go away entirely early on in postmenopause.

Perimenopause vs. menopause symptoms

So, what are these symptoms that you may experience during perimenopause and menopause? 

Each person’s experience of perimenopause and menopause is unique, but there are often commonalities. Symptoms can be both physical and emotional, and can range from frustrating to unbearable. 

Signs of perimenopause include:

• Changes in cycle length
• Heavier periods
• Irregular bleeding or spotting
• Decreasing fertility

Common symptoms that may occur during both perimenopause and menopause include:

• Hot flashes and night sweats (sometimes followed by chills)
• Sleep disturbances or insomnia
• Brain fog
• Increased headaches or migraine
• Mood changes or mood swings
• Vaginal dryness and discomfort
• Decreased sex drive
• Joint pain
• Thinning hair
• Dry skin
• Weight gain and slower metabolism

Other symptoms and conditions are more likely to pop up around menopause and postmenopause, like:

• Increased bone loss and higher risk of osteoporosis
• Higher risk of heart disease

Am I in perimenopause or menopause?

To recap: after all your years in premenopause, you get to perimenopause. Then, after a few years in transition, you reach menopause and your final menstrual period. Now, you’re in postmenopause.

We commonly refer to this whole span of biological shifts as “menopause,” even though much of it is actually perimenopause. When someone says “I’m menopausal,” chances are they’re actually perimenopausal and on their way to official menopause.

Many of the symptoms we associate with menopause are also symptoms of perimenopause. This can lead to confusion about which stage you’re in. It may also make the distinction between the two seem more like a technicality than anything else.

Far from it! One critical difference between perimenopause and menopause both distinguishes the two and helps you determine which stage you’re in: pregnancy.

‍During perimenopause, you can still get pregnant. This is because you’re still experiencing menstrual cycles, meaning you’re still ovulating (albeit irregularly). And where there’s ovulation, there’s a possibility for pregnancy.

>>MORE: Everything You Need to Know About Perimenopause Ovulation (and How to Track It)

Once you’ve hit menopause, on the other hand, your menstrual cycles end and so does your ovulation. In other words, pregnancy is no longer possible.

If you’re perimenopausal and don’t want to get pregnant, you should continue to use birth control until you’ve gone at least one full year without a period. On the flip side, if you’re trying to conceive, don’t lose hope: pregnancy can still happen, whether naturally or with the help of reproductive technologies.

If you’re not sure whether you’re still ovulating, at-home fertility test kits and perimenopause test kits can help you track your cycles, hormones, and ovulation.

Menstrual cycles, ovulation, and pregnancy—therein lies the dividing line separating perimenopause vs. menopause.

Perimenopause vs. menopause: the bottom line

With time and age come different phases of your life. Biologically speaking, these phases are generally divided into premenopause, perimenopause, menopause, and postmenopause.

As you start transitioning out of the reproductive years, you enter perimenopause. You can still get pregnant at this time. Perimenopause ends once you’ve gone 12 consecutive months without bleeding or spotting. Now, you’ve reached menopause. After menopause, you can no longer get pregnant.

For many people, the biological shift from reproductive years to postmenopause triggers physical and emotional symptoms, many of which overlap across perimenopause and menopause. Postmenopause may help ease symptoms for some people, although this may take time and may not be the case for everyone. 

If you’re having trouble with any symptoms, whether around perimenopause, menopause, or postmenopause, consider talking with your doctor about how to get relief. Options include lifestyle changes and medical treatment.

There’s no one right path to menopause. Each person’s experience of the transition into this stage of life is different. Understanding where you are in the transition can help you be more equipped to face the changes you’ll experience and adapt to your new body.