Irregular periods in perimenopause

Periods that arrive closer together, further apart, lighter, heavier, or just less predictably are one of the earliest and most common signs of perimenopause. In the STRAW+10 clinical staging framework, this is formally described as early menopausal transition — a persistent difference of 7 days or more between consecutive cycle lengths. UK guideline NICE NG23 also uses menstrual cycle changes, alongside new vasomotor symptoms, to help identify perimenopause without needing blood tests in people 45 and over.

What "irregular" actually covers

Perimenopausal cycle changes can go in more than one direction, and both are expected:

• Shorter cycles, sometimes with periods arriving closer together than before
• Longer cycles, with gaps stretching out as ovulation becomes less frequent
• Skipped periods, which become more common as you move toward late perimenopause
• Lighter or heavier flow than your usual pattern (see our dedicated page on heavy periods in perimenopause if flow itself is the main issue)

When irregularity needs a doctor's check

Most cycle irregularity in perimenopause is fine to simply track. A smaller set of patterns needs medical attention instead:

Track your pattern

Because the staging itself depends on comparing cycle lengths over time, a few months of tracking is more useful than trying to judge a single cycle. Our perimenopause stage guide uses your logged pattern to estimate where you likely are, and our 12-month counter picks up once your periods actually stop.

If you've had unexplained bleeding changes and want more clarity before your appointment, see is there a blood test for perimenopause? for what testing can and can't tell you.