Heavy menstrual bleeding (HMB), or menorrhagia, is excessive menstrual blood loss that affects a woman’s quality of life. It is common, often under-recognised, and a leading cause of iron-deficiency anaemia in women. With proper assessment, most causes can be treated.
What counts as “heavy”?
A period is heavy when it disrupts your physical, emotional, social or working life, not by a number on a measuring cup.
Your periods may be heavy if you:
- Change a pad or tampon every 1–2 hours or empty a menstrual cup more often than recommended.
- Need two products at once, such as a pad and a tampon, or wake at night to change.
- Bleed for more than 7 days.
- Pass clots about 2.5 cm across or bigger, roughly the size of a $1 coin.
- Leak through to your clothes, bedding or office chair.
- Skip exercise, social plans, school or work because of your period.
- Often feel tired, dizzy or short of breath.
In Singapore, an estimated 1 in 10 to 1 in 20 women have heavy menstrual bleeding. Many still put off seeing a doctor. They may have always had heavy periods, or their mother and sisters did too, or they find it awkward to talk about. Singapore doctors note that some women wait so long that they need hospital care and a blood transfusion.
If your “normal” has always been heavy, it may never have been normal at all. See your GP or a gynaecologist if your periods affect your daily life, you have bad period pain, or you have any bleeding after menopause.
What causes heavy periods?
Heavy periods can happen for many different reasons, and most of them can be treated.
Structural changes in the womb:
- Polyps: small, usually harmless growths on the inside lining of the womb.
- Fibroids: lumps of muscle in the womb that aren’t cancer. They’re very common, and whether they cause problems depends on how big they are and where they sit.
- Adenomyosis: when the womb lining grows into the muscle wall around it. It tends to make periods painful as well as heavy.
Other causes:
- Irregular ovulation or other hormonal imbalances.
- Blood clotting disorders caused by underlying medical conditions
- Medicines: blood thinners and some cancer treatments can make periods heavier.
Why your iron matters
When you bleed heavily every month, you can lose iron faster than your food can top it up. Over time, this leads to anaemia, which simply means your blood is low on iron. At first, you may feel totally fine, so lots of women have no idea it’s happening. As it gets worse, you might notice:
- feeling tired even after a good night’s sleep
- dizziness or feeling light-headed
- getting puffed out or feeling your heart race, even on the stairs
- looking pale, getting headaches or finding it hard to focus
In fact, many women only find out they’re low in iron at a health screening or when they try to donate blood. If it’s left alone, severe anaemia can lead to fainting, falls and extra strain on your heart. A simple blood test can check your levels.
What to expect at your appointment
Usually, it’s a chat about your periods, a check-up, a blood test and often an ultrasound scan. Some women need a closer look inside the womb with a tiny camera, or a small sample of the lining, especially if they’re over 40. Most of this can be done right in the clinic.
Tip: track two or three periods in an app before your visit, noting how often you change your pad and any clots or leaks.
What can be done about it?
Most women feel much better with medicine alone. The best option depends on the cause, your age and whether you’d like children in future. If you’re low in iron, iron tablets will help too.
Heavy periods are common, but you don’t have to put up with them. If your period is draining your energy or getting in the way of life, talk to a doctor. Your period should fit around your life, not the other way round.
This article is for general information only and isn’t a substitute for medical advice.
