Understanding Perimenopause

Perimenopause is the natural transition leading up to menopause. 

Symptoms and timing vary widely, but relief and support are available. 

What it is

Perimenopause begins when cycles become irregular and ends 12 months after the final period.

How Long

Most people experience 3–4 years, but it can be shorter or last up to a decade.

It's individual

Some have minimal symptoms; others notice hot flashes, sleep change, mood shifts, or heavy bleeding.

What is perimenopause?

You’re in your 40s, you wake up in a sweat at night, and your periods are erratic and often accompanied by heavy bleeding: Chances are, you’re going through perimenopause.

Many women experience an array of symptoms as their hormones shift during the months or years leading up to menopause — that is, the natural end of menstruation.

Perimenopause (“peri” = around) is the extended transition leading up to menopause. 

It begins with irregular menstrual cycles — courtesy of declining ovarian function —

The transition ends one year after the last menstrual period.

Timing varies: the average duration is 3–4 years, but some experience just a few months while others may have symptoms for up to a decade.

What’s happening with hormones?

During reproductive years, estrogen rises and falls predictably with each cycle, guided by FSH and LH. In the transition, progesterone production wanes in the late 30s, the number and quality of follicles diminish, and estrogen can swing higher or drop suddenly.

By our late 30s, we don’t produce as much progesterone. The number and quality of follicles also diminishes, causing a decline in estrogen production and fewer ovulations. As a result, by our 40s, cycle length and menstrual flow may vary and periods may become irregular.

Over time, FSH rises in an effort to stimulate the ovaries. These fluctuations contribute to symptoms such as hot flashes, irregular bleeding, and sleep changes.

ESTROGEN

Can spike or dip unpredictably

PROGESTERONE

Gradually declines by late 30s

FSH

Rises over time as ovaries respond less

Common symptoms

Symptoms can precede the final period by up to 10 years and vary from person to person.

Hot flashes & night sweats

Sudden warmth, flushing, and sweating lasting 1–5 minutes; frequency ranges from occasional to multiple times daily.

Irregular or heavy bleeding

Cycles may shorten, lengthen, or skip; heavier flow can result from less progesterone and endometrial buildup.

Vaginal & vulvar changes

Dryness, irritation, and discomfort with intercourse may occur; these often worsen after menopause without treatment.

Sleep disturbance

About 40% report trouble falling asleep or staying asleep.

Mood and memory

Some experience mood shifts, irritability, or difficulty concentrating. Overall depression risk does not increase after 45.

Libido changes

Desire may decrease due to symptoms, stress, or vaginal discomfort.

Frequently asked questions

Irregular cycles in your 40s plus symptoms like hot flashes, sleep change, or vaginal dryness point to the transition. A single blood test (FSH) isn’t reliable because levels fluctuate—clinical history is key.

Yes—until you’ve had 12 consecutive months without a period (and are off hormones), pregnancy is still possible.

Yes. They commonly begin during perimenopause and can continue for 1–2 years after menopause for many people.

Many people find relief by avoiding personal triggers, layering clothing, practicing paced breathing, and improving sleep routines.

Let's make a plan that fits you...

If perimenopausal symptoms are affecting your daily life, we can help you choose safe and effective options.

We encourage you to call our office for a consultation.

County Obstetrics & Gynecology

STL Leaders in Women’s Healthcare

Board Certified Physician:

Dr. Lawrence V. Boveri

Dr. Stephen A. Boveri

Our Location

1859 Bowles Avenue

Suite 103

Fenton, MO 63026

Our Hours:

Monday:              9:00 – 5:00

Tuesday:             9:00 – 5:00

Wednesday:       9:00 – 5:00

Thursday:           9:00 – 3:00

Friday:                 9:00 – 12:00