It isn't one symptom. It's a pattern.

Most women know two perimenopause symptoms: hot flashes and periods that change. The full list is much longer, and a lot of it gets investigated one piece at a time — a GP appointment for joint pain, another for sleep, another for anxiety — without anyone joining the dots.

First, what perimenopause is

Perimenopause is the transition before your periods stop for good. It usually starts in your mid-to-late 40s, and it lasts about four years on average, though anywhere from two to eight is normal (Office on Women's Health). You've reached menopause once it has been a full year since your last period. Everything before that — the years you're still bleeding, however irregularly — is perimenopause.

The symptoms people expect

Changes to your periods

Usually the first sign. Cycles get shorter, then longer, then unpredictable; bleeding can be heavier or lighter. Clinicians stage it by variability: a persistent difference of seven days or more between consecutive cycles marks the early transition, and gaps of sixty days or more mark the late one (ASRM). Read more in why your period tracker stops making sense.

Hot flashes and night sweats

Up to 80% of women have them during the transition, and they last longer than most people are told: in the SWAN study, the median total duration of frequent hot flashes was 7.4 years — longer still for women whose flashes began early in perimenopause (Avis et al., JAMA Internal Medicine 2015).

The symptoms nobody mentions

Waking at 3am

Between 40% and 60% of women in the transition report disturbed sleep, and night-time hot flashes are a big part of it — an awakening coincided with 69% of measured hot flashes in one study (Baker et al.). More in waking at 3am in your 40s.

Brain fog and lost words

About two-thirds of women report memory complaints during the transition. The good news from SWAN: the dip in learning seen during perimenopause appears to be time-limited (SWAN fact sheet). More in perimenopause brain fog.

Heart palpitations

A faster, harder or more noticeable heartbeat is on the NHS list of symptoms (NHS). In SWAN, about half of women fell into groups with moderate or high rates of palpitations through perimenopause and early postmenopause — and those palpitations weren't linked to signs of heart disease (Palpitations across the menopause transition in SWAN). Still, new palpitations deserve a check with a clinician, every time.

Joint and muscle pain

Aches and stiffness are listed by both the NHS and NICE among menopause symptoms (NICE guideline NG23). Many women also describe painful, stiff shoulders around this time. It's worth mentioning perimenopause when you're seen for them, so the pain is looked at in context.

Itchy or dry skin, new sensitivities

Dry and itchy skin appears on the NHS list, alongside headaches and migraines that are worse than usual, hair thinning, sensitive teeth and gums, and more frequent urinary infections (NHS).

Mood: anxiety, low mood, a very short fuse

Mood swings, low mood and irritability are common and often blamed on everything else first (NHS). If it's more than a short fuse — and especially if it's dark — please talk to someone. Mood in midlife deserves proper care.

Why the list matters: seeing it together

Each of these symptoms has other possible causes, which is exactly why they get investigated separately. What makes perimenopause visible is the combination and the timing: which symptoms travel together, how often, and whether they cluster around your cycle. That's hard to reconstruct from memory in a ten-minute appointment.

For women over 45, NICE advises that perimenopause can be diagnosed from symptoms and irregular periods alone, without a blood test (NICE guideline NG23). So the record you bring is the evidence.