Regular cycles typically run 21–35 days with 2–7 days of bleeding.
Irregular menstruation means cycles that vary in timing, flow, or
duration, and may be linked to lifestyle, hormonal, or medical
factors.
What a Regular Cycle Looks Like
Cycle length: Usually 21–35 days (average ~28
days).
Bleeding duration: Typically 2–7 days.
Flow amount: About 20–90 ml per period.
Predictability: Generally follows a steady
pattern over months.
What Counts as Irregular
Cycles shorter than 21 days or longer than 35 days.
Month-to-month variation greater than 7–9 days.
Missed periods, unusually heavy/light flow, or spotting between
periods.
Common Causes
Hormonal imbalances (thyroid issues, PCOS).
Stress and anxiety.
Significant weight loss/gain or excessive exercise.