Heavy periods are far from rare in Australia. The government-funded health service healthdirect says about 1 in 4 females experience heavy periods, also called menorrhagia, and describes them as blood loss that affects your physical health, social life and emotional wellbeing.
So if you are wondering why your period is so heavy, the honest answer is that there are several possible reasons, and sometimes no clear one at all. Here is how Australian health sources group the heavy period causes, and when to talk to your GP.
Quick answer: healthdirect groups the causes of heavy periods into hormone imbalances (including PCOS, an underactive thyroid, puberty and perimenopause), changes in the uterus such as fibroids, polyps, adenomyosis or endometriosis, blood clotting disorders such as von Willebrand disease, and medicines like blood thinners. In many cases, the cause is not known.
What makes your period heavy?
Most heavy flow causes sit in four groups, according to healthdirect:
- Hormone imbalances: polycystic ovary syndrome (PCOS), an underactive thyroid, hormonal medicines, perimenopause and puberty.
- Changes in the uterus: fibroids, polyps, a thickened uterine lining, adenomyosis, endometriosis and, rarely, endometrial cancer.
- Blood clotting disorders: von Willebrand disease, platelet function disorders or low platelet levels.
- Medicines: such as blood thinners.
healthdirect is clear that in many cases the cause is not known, which is worth remembering if tests come back normal.
What hormone causes heavy periods?
Australian sources don't single out one hormone; they point to hormone imbalances in general. healthdirect lists PCOS, an underactive thyroid and hormonal medicines, as well as two life stages when hormones shift a lot: puberty and perimenopause. That helps explain why teens who have just started their periods, and people in their forties, often notice a heavier flow.
Why is my period so heavy all of a sudden?
A sudden change deserves attention, and healthdirect lists suddenly much heavier bleeding as a reason to seek urgent care. It also advises urgent care if a heavy period comes with signs of anaemia, such as dizziness or weakness. A new medicine, such as a blood thinner or a hormonal medicine, is one possible explanation to raise with your doctor, but a sudden shift should be checked rather than guessed at.
Are big clots a sign of a heavy period?
Large clots can be a sign of a heavy flow. healthdirect lists passing blood clots larger than a 50 cent coin among the signs of heavy periods, and Jean Hailes for Women's Health says small clots are normal, but if you see lots of clots or clots bigger than a 50-cent coin, talk to your doctor.
When to see a GP
healthdirect says to see your doctor if you have heavy periods or your periods affect your everyday life. Also book in if you notice:
- spotting between periods or bleeding after sex;
- any bleeding after menopause;
- a period lasting more than 8 days;
- needing to change a pad or tampon every 1 to 2 hours, or overnight;
- tiredness, pale skin or shortness of breath alongside heavy bleeding.
For urgent care, healthdirect suggests a Medicare Urgent Care Clinic or a hospital emergency department. In an emergency, call triple zero (000). For free health advice any time, you can call healthdirect on 1800 022 222.
Frequently asked questions
Can an underactive thyroid cause heavy periods?
Yes. healthdirect lists an underactive thyroid among the hormone imbalances that can cause heavy periods, alongside PCOS, hormonal medicines, puberty and perimenopause. If you also feel unusually tired or notice other changes, mention them to your GP, who can decide whether blood tests are worthwhile for you.
Is adenomyosis a cause of heavy periods?
It is one of them. healthdirect includes adenomyosis in its list of changes to the uterus that can lead to heavy periods, along with fibroids, polyps, a thickened lining and endometriosis. Your GP can talk you through the tests that might help work out whether a uterine change is behind your heavier flow.
Why are my periods heavier in my forties?
healthdirect lists perimenopause, the years leading up to menopause, as one of the hormone-related causes of heavy periods. A heavier flow at this stage is common, but it still deserves a check if it affects your daily life, and healthdirect advises seeing a doctor about any bleeding after menopause.
What can I do about heavy periods?
Treatment depends on the cause, says healthdirect. Self-care ideas include using more than one type of protection, eating well, managing stress, sleeping well and staying active. Medical options include tranexamic acid, anti-inflammatory medicines, a hormonal IUD or the pill, plus iron if your levels are low.
Curious about clots? Read are period blood clots normal.
If you bleed heavily, the Lunette period cup Size 2 holds 30 ml and has measuring lines, so you can see how much your flow changes from day to day. Lunette suggests Size 2 for a heavier flow; compare both menstrual cup sizes in the size guide.
General information only, not medical advice. Please see your GP or call healthdirect if you are worried about your periods.
