Perimenopause and irregular periods: what to know

As ovarian hormone signals fluctuate, ovulation may happen less predictably. Periods may arrive earlier or later, last for a different length of time, or vary in flow; a missed period can also occur. Other explanations include pregnancy, [Anovulation](/conditions/anovulation/), thyroid problems, [Polycystic Ovary Syndrome](/conditions/polycystic-ovary-syndrome/), medication effects, or [Premature Ovarian Insufficiency](/conditions/premature-ovarian-insufficiency/).

Use a calendar or app to record bleeding dates, flow, pain, missed periods, hot flushes, sleep changes, and medicines. Consider a pregnancy test when relevant. A clinician may review your history, check for anaemia or other conditions, and discuss options such as the [Combined Pill](/treatments/contraception-and-family-planning/combined-pill/) when suitable. [Metformin for PCOS](/treatments/medical-gynaecology/metformin-for-pcos/) is relevant only when PCOS is diagnosed and treatment is advised.

Arrange an assessment for bleeding between periods, after sex, unusually heavy bleeding, persistent pelvic pain, or a marked change in your established pattern. Seek urgent help for severe pain, faintness, or bleeding that is difficult to control. Read about [Irregular Periods](/symptoms/irregular-periods/) alongside information on [Perimenopause](/conditions/perimenopause/) before your appointment.

Could pregnancy, anovulation, PCOS, thyroid disease, or another cause explain my pattern? Do I need tests? How can I manage bleeding, contraception, or fertility concerns while my cycles change?