What should you know about sudden irregular periods?

A period may arrive early, late, become lighter or heavier, or be missed when ovulation changes. Stress, substantial changes in exercise or eating, illness, and some medicines can affect the cycle. Anovulation means an egg is not released during a cycle and can lead to unpredictable bleeding. Perimenopause can also make cycles less predictable. Polycystic ovary syndrome and premature ovarian insufficiency are other conditions a clinician may consider, particularly when irregularity persists or comes with acne, increased facial hair, hot flushes, or fertility concerns.

Record the first day of each bleed, how long it lasts, whether the flow is unusually heavy, and any pain or bleeding between periods. Note pregnancy possibility, contraception changes, new medicines, weight or exercise changes, stress, and symptoms such as hot flushes or unusual discharge. Take a pregnancy test when pregnancy is possible. Arrange a routine appointment if the pattern continues, repeatedly changes, or matters to your plans for pregnancy. Treatment depends on the cause; options may include cycle support such as the Combined Pill or treatment directed at Polycystic Ovary Syndrome, rather than treating the calendar change alone.

Seek urgent medical help for very heavy bleeding, faintness, severe or one-sided pelvic pain, or bleeding during a possible pregnancy. Contact a clinician promptly for bleeding after sex, repeated bleeding between periods, or a missed period with significant pain. These features need assessment because they can signal pregnancy-related problems, infection, or another condition requiring timely care.

Ask whether your pattern suggests anovulation, perimenopause, polycystic ovary syndrome, or premature ovarian insufficiency; whether pregnancy testing or other checks are appropriate; and which treatment fits your bleeding pattern, health history, and pregnancy plans.