More than reproduction

The menstrual cycle reflects nutrition, stress, sleep, body composition and thyroid function. Changes in cycle length or flow often appear long before other symptoms.

A normal cycle

  • 21–35 days in length.
  • 2–7 days of bleeding.
  • Predictable from month to month after age 20.

Red flags worth checking

  • Cycles consistently longer than 35 days.
  • Severe pain that interferes with daily life.
  • Bleeding between periods.
  • Sudden change in flow heaviness.

These can be signs of PCOS, endometriosis, thyroid disease or fibroids — all manageable with the right care.