Early signs of perimenopause: the first changes to notice

The first signs of perimenopause are usually small changes in your period: a cycle that comes a few days sooner than it used to, bleeding that is heavier or lighter, and later, cycle lengths that swing by a week or more. Around the same time, many women notice broken sleep, the first night sweats, or a mood that feels less steady. Each of these is common on its own; the combination, in your 40s, is what points to perimenopause.

Why the first signs are easy to miss

Perimenopause does not announce itself. The National Institute on Aging (NIA) describes the transition as usually starting with changes in menstrual cycle patterns, often accompanied by hot flashes or other symptoms, and says most women begin it between ages 45 and 55. At the start, periods still arrive more or less on schedule, so the early changes are easy to put down to stress, a busy year or getting older.

Researchers date the transition using the STRAW+10 staging system, which defines each stage by bleeding patterns and is meant to apply regardless of a woman’s age, ethnicity, body size or lifestyle. Our guide to what perimenopause is walks through those stages. The reason early signs come and go is that hormones fluctuate rather than fall steadily, which we explain in what happens to your hormones in perimenopause.

Your cycle: usually the first clue

The Menopause Society describes a typical early sequence. At first the changes are subtle: it is common for cycles to become a little shorter than usual, and the number of bleeding days may be fewer or greater, with heavier or lighter flow. As perimenopause progresses, cycle length may vary by 7 days or more. An occasional skipped period comes next, and in the late transition, gaps of 60 days or more.

Change	What you might notice
Slightly shorter cycles	Your period arrives a few days sooner than you are used to
Different flow	More or fewer bleeding days; heavier or lighter bleeding
Variable cycle length	Cycles that differ by 7 days or more from one to the next
Skipped periods	An occasional missed period early on; gaps of 60 days or more later

Because most women have a fairly consistent pattern in the years before, these shifts tend to be noticeable once you start looking. For the full progression and the bleeding changes that are not normal, see how periods change in perimenopause.

Sleep that starts to break up

Trouble sleeping is one of the most common early complaints. In a SWAN community survey of 12,603 women aged 40 to 55, 38% reported difficulty sleeping in the previous two weeks. Age-adjusted rates were highest in late perimenopause, at 45.4%. Stage of the transition was linked to sleep difficulty independently of other factors, while older age on its own was not.

The NIA describes both patterns: trouble falling asleep, or waking too early, sometimes because of a night sweat or a need to urinate, and then struggling to get back to sleep. If early waking is your main problem, see why perimenopause wakes you at 3 am.

Hot flashes and night sweats, sometimes before periods change much

The Menopause Society notes that one large, diverse US study found up to 80% of women experience hot flashes or night sweats at some point during the transition. A hot flash typically lasts 1 to 5 minutes and can come with sweating, chills, anxiety or a racing heart. Night sweats are the same event during sleep.

They do not always wait for late perimenopause. In SWAN, among 1,449 women with frequent hot flashes or night sweats, the median total duration was 7.4 years. Women who were still premenopausal or in early perimenopause when frequent symptoms began had the longest duration, a median of more than 11.8 years. Early onset is a reason to look at treatment rather than wait it out.

Mood, focus and headaches

Mood changes are an early sign many women do not connect to hormones. The Menopause Society describes a window of vulnerability in which some women are more sensitive to perimenopausal hormone shifts, and notes that women with a history of depressed mood earlier in life are at greatest risk. In SWAN’s Pittsburgh site, women were two to four times more likely to have a major depressive episode when they were perimenopausal or early postmenopausal than when they were premenopausal, independent of a past history of depression, upsetting life events and hot flashes.

Other early changes the Menopause Society highlights:

• Forgetfulness and brain fog. Forty to sixty percent of midlife women report cognitive symptoms such as forgetfulness during the transition. Changes are typically mild and within normal limits.
• Headaches. Fluctuating estrogen may cause hormone-related headaches, including migraine, to increase.

How common each sign is

Sign	What the research shows
Cycle changes	Usually the first change; early cycles are often a little shorter
Hot flashes and night sweats	Up to 80% of women at some point in the transition
Trouble sleeping	38% of women aged 40 to 55; 45.4% in late perimenopause
Depression	Two to four times higher odds of a major depressive episode in perimenopause and early postmenopause
Forgetfulness	Reported by 40 to 60% of midlife women
Vaginal dryness	Often not noticed until after menopause

Vaginal dryness is the exception to the early pattern: the Menopause Society notes that many women do not notice symptoms of genitourinary syndrome of menopause during perimenopause.

What else it could be

None of these signs belongs only to perimenopause. Thyroid disease, pregnancy, iron deficiency from heavy periods, depression, sleep apnea and some medications can all produce a similar picture. That matters most when changes start before 40 or when one symptom dominates without any change in your cycle. A short set of tests can rule these out, and a clinician can tell you which ones fit your situation.

How to tell whether it is a pattern

Single bad nights or one odd cycle mean little. A pattern over two or three months means more. The Menopause Society suggests tracking bleeding on a calendar or smartphone app so it can be reviewed easily. Note:

• The first day of each period and how many days you bleed
• Whether flow is heavier or lighter than your usual
• Night sweats, hot flashes and early waking
• Mood, irritability and concentration on a simple 1 to 5 scale

The symptom check can help you organize what you are noticing. A blood test is unlikely to add much, because hormone levels swing in this phase; see why hormone tests are often normal.

When to see a clinician

• You are under 40 and your cycles have changed, or your periods have stopped for several months
• Your periods come very close together, last more than a week or are heavy, or you bleed between periods or after sex; the NIA lists all of these as reasons to see a doctor
• You have any bleeding or spotting after 12 months without a period
• Sleep, mood or hot flashes are affecting your work, relationships or daily life
• You have thoughts of harming yourself; seek help the same day

Early perimenopause symptoms are treatable, and you do not need to wait for your periods to stop. To find a clinician who treats this stage, search the directory or look for an ob-gyn near you.