Heavy period with Mirena: what to know

Mirena is a hormonal intrauterine device that often changes the pattern of menstrual bleeding. Spotting or irregular bleeding can occur after insertion, while a sudden change after a settled pattern deserves review. Causes can include the device shifting, pregnancy, an infection, or a condition affecting the womb such as fibroids or adenomyosis. Heavy bleeding itself can lead to iron deficiency anaemia, which may cause tiredness, breathlessness, headaches, or a racing heartbeat. A heavy period is a symptom, not a diagnosis; most people with heavy bleeding do not have the same underlying cause.

Note when the bleeding began, how often you change pads or tampons, whether clots are present, and any pelvic pain. Arrange a clinician review if the pattern is different from your usual Mirena bleeding or is affecting sleep, work, or daily activities. The clinician may check the device position, ask about pregnancy possibility and medicines, examine you, and arrange blood tests for anaemia. Do not try to remove the device yourself. Keep taking prescribed medicines unless a clinician tells you otherwise.

Seek urgent care for bleeding that is rapidly soaking pads, fainting, severe or one-sided pelvic pain, shoulder-tip pain, fever, or a positive pregnancy test with pain or bleeding. These symptoms can signal significant blood loss, infection, or a pregnancy complication. If you feel weak, confused, or short of breath at rest, do not drive yourself. Contact a clinician promptly for a missing or changed IUD string, new pain during sex, or bleeding that continues between periods.

Ask: Could Mirena have moved? Do I need a pregnancy test, pelvic examination, ultrasound, or blood count? Could another condition explain the bleeding? Which treatment options fit my health history, contraception needs, and plans for future pregnancy?