Why does iron deficiency anaemia cause heavy periods?

The relationship can run in both directions. Heavy menstrual bleeding can remove more iron than the body replaces, gradually causing iron deficiency anaemia. Once iron stores are low, reduced oxygen-carrying capacity can leave you tired, breathless, dizzy, or prone to palpitations. Iron deficiency may also affect the processes that help the uterine lining and blood vessels settle after a period, so bleeding can become harder to control. Heavy bleeding has other possible causes, including fibroids, hormonal changes, medicines, and pregnancy-related problems.

Book an appointment if periods are becoming heavier, lasting longer than expected, or disrupting daily activities. A clinician may ask about bleeding pattern, check for anaemia with blood tests, and investigate why the periods are heavy. Treatment may include iron replacement and a plan to reduce menstrual blood loss. Take iron only as advised, because the correct dose and duration depend on your results and health history.

Get urgent help if bleeding is soaking through protection repeatedly, you feel faint, have chest pain, severe breathlessness, confusion, or weakness that is rapidly worsening. Seek prompt advice for bleeding during pregnancy or after menopause, or when heavy periods are accompanied by severe pelvic pain.

Ask whether your blood count and iron stores need testing, what may be driving the bleeding, and which treatment can address both the low iron and the menstrual loss. Mention dietary changes, medicines, and any bowel symptoms affecting iron tablets.