Am I in perimenopause? The stages, explained simply
The short answer
Menopause is a single point: 12 months after your final period, at an average age of 51 in the US. Before it is perimenopause, often starting in your 40s and lasting about four years on average. A change of seven or more days in your usual cycle length is the classic early sign.
| Stage | What's happening | Typical signs | Typical timing |
|---|---|---|---|
| Early perimenopause | Hormones start to swing | Cycle length varies by 7+ days; new PMS, mood or sleep changes | Often early to mid 40s |
| Late perimenopause | Swings get bigger, periods get sparse | 60+ days between periods; hot flashes often peak | Late 40s to early 50s |
| Menopause | 12 months with no period | Confirmed in hindsight | Average 51; most between 45 and 55 |
| Postmenopause | Estrogen settles lower | Hot flashes may continue; bone, heart, vaginal and bladder health come into focus | The rest of your life |
Three things that surprise almost everyone
- It can start in your late 30s or early 40s. Mood, anxiety and sleep changes often arrive years before hot flashes.
- A single blood test usually can't confirm perimenopause. Hormone levels swing day to day, so most clinicians diagnose it from your age, cycle and symptoms. That's why a symptom record matters.
- Early or sudden menopause is different. Menopause before 40 (about 1 in 100 women), before 45, or after surgery that removes the ovaries carries higher long-term bone and heart risks and deserves specialist care.
Quick self-check
- Cycles changing in length, flow or timing? Likely perimenopause.
- No period for 12 months, with no other cause like pregnancy, an IUD or medication? You've reached menopause.
- Had a hysterectomy but kept your ovaries? Periods can't guide you; track symptoms instead.
Not sure? The free Symptom Snapshot shows which pattern your answers resemble and gives you questions for your clinician.
Questions
What is the average age of menopause?
51 in the United States, with most women reaching it between 45 and 55.
How do I know perimenopause has started?
The classic early marker is a persistent change of seven or more days in your usual cycle length, often alongside new sleep, mood or PMS changes.
Want this in one place? Track your symptoms with the free Symptom Snapshot, or get The Sisu Season Guide for the full picture.
Education and personal experience, not medical advice. Talk with your own clinician before making health decisions.