Women's Conditions
What causes irregular periods? Gynecologist in Seoul, Korea
The short answer
Common causes include stress, travel and lifestyle changes, significant weight change, polycystic ovary syndrome (PCOS), thyroid problems, high prolactin, breastfeeding, approaching menopause, and hormonal contraception. Pregnancy must always be ruled out first. Ultrasound and a hormone panel help identify the cause.
A normal cycle is 21–35 days. If yours falls outside that range or varies widely, book a hormone test with ultrasound (Dami Basic 3). Treatment depends on the cause.
Answered by Dami Women's Clinic (다미산부인과의원), Yeouido, Seoul · Dr. Ko Sang-hyun, OB/GYN. General information, not a diagnosis. Emergencies in Korea: call 119. Medical disclaimer · International Patient Center