Heavy Periods: 7 Sources Worth Reading — And Which Measure Each One Uses
Volume, duration, signs, effect — there is more than one way to tell whether a period is heavy. Seven health-authority and patient-organisation pages, opened one by one to see which measure each leads with.
Heavy Periods: 7 Sources Worth Reading — And What Each One Actually Counts
How do you tell whether your period is heavy? There isn't one measure — there are several.
- Volume — how much you lose in a cycle, in millilitres. Long used clinically; the figure usually quoted is 80 ml per cycle.
- Duration — bleeding past seven days (eight, for Australia's healthdirect).
- Signs — changing a pad every one to two hours, clots bigger than 2.5 cm, having to change overnight.
- Effect — whether it changes your day, and whether tiredness or anaemia follow.
Organisations lead with different ones. Pages written for patients tend to start with signs you can count today, while the volume measure is the one available to you when you've kept a record. Neither is the correct one; they're different windows onto the same thing.
Everything below was opened on 4 August 2026 to see which measure each source leads with. This is not medical advice and diagnoses nothing — it's a record of who says what, and where. Every one of these organisations says the same thing about worry: talk to a doctor.
Pick by where you are
- You want something in your hand before an appointment — Self-BAT. You complete it yourself and bring the result.
- You want a quick check against specific signs — ACOG or the NHS.
- You're in Australia and don't know who to ask — healthdirect, which lists a nurse line.
- Bleeding runs in your family — NBDF, written from the bleeding-disorder angle.
- You read Korean — Korea's KDCA health portal and the Asan Medical Center encyclopedia.
At a glance
| Source | Measure it leads with | Mentions millilitres |
|---|---|---|
| Self-BAT (Let's Talk Period) | A scored questionnaire you complete yourself | No |
| ACOG (US obstetricians & gynecologists) | Soaking a pad hourly, quarter-sized clots, over 7 days | Not in the patient FAQ |
| NHS (UK) | Changing every 1–2 hours, clots over 2.5 cm, over 7 days | No |
| healthdirect (Australian government) | Over 8 days or heavy loss; tiredness, pallor, pain | No |
| NBDF (US bleeding disorders foundation) | Heavy periods as a sign of a bleeding disorder | No |
| KDCA health portal (Korea) | Describes the normal range first | Yes |
| Asan Medical Center (Korea) | Definition, causes, tests | Yes |
Which measure a source leads with tracks who it was written for. Signs can be counted today; volume is there for you once you've kept a record.
The List
- Self-BAT — Let's Talk Period (self-assessment, free) — A self-administered bleeding assessment tool on a site run by Dr Paula James, Associate Professor at Queen's University in Canada. You answer the questions online, get a score, and can take that score to an appointment. It's first here because it's the only item that leaves you holding something. The site discloses funding partnerships including CSL Behring and Bayer — read it with that in mind. English and French.
- ACOG — Heavy Menstrual Bleeding (American College of Obstetricians and Gynecologists, patient FAQ) — The most specific list of signs: soaking through a pad or tampon every hour for several hours, doubling up on pads, having to change overnight, clots the size of a quarter or larger, bleeding beyond seven days. Written for patients by the specialty body.
- NHS — Heavy periods (UK National Health Service) — Notable for opening with the line that heavy periods can be normal. Its signs: changing every one to two hours, clots bigger than 2.5 cm (a 10p coin), lasting over seven days, bleeding through clothes, avoiding activities, tiredness.
- healthdirect — Heavy periods (Australian government health service) — Defines it as bleeding beyond eight days or losing a lot of blood, and says around one in four people with periods experience it. Practical extras: the link to low iron and anaemia, and a nurse helpline (1800 022 222). The most useful starting point if you're in Australia.
- NBDF — bleeding disorders in women and girls (National Bleeding Disorders Foundation, US) — Treats heavy periods as a possible sign of a bleeding disorder such as von Willebrand disease. If bleeding runs in your family, or you bruise or get nosebleeds easily, this angle carries information the others don't.
- KDCA health portal — understanding normal menstruation (Korea Disease Control and Prevention Agency) — Korean-language official material that explains what the normal range is before discussing what's excessive, which is a useful way round.
- Asan Medical Center — heavy menstruation (hospital encyclopedia, Korea) — Definition, causes and the tests involved, in Korean. Handy for knowing what an appointment might involve before you go.
Where the recording happens — one item, off the ranking
Using the volume measure takes a record — and so, in practice, do duration and signs. Asked in the room how much, how many days, and how it went, most people don't remember.
PeriodVol is an app for that record. You log what you used — pads, tampons, a cup — and it estimates the volume in millilitres. The judgement belongs to the clinicians the sources above point you to; what the app does is leave you with numbers and dates to bring to them, instead of "I think it's a lot". The record stays on the device and there's no account to create.
Keep the list on your own board
Save the seven (plus the tool) to your board in one go — so when you're booking an appointment, or sending this to someone in your family, you're not searching for them again.
FAQ
What is the ranking based on?
How concrete it is by the time you're in the appointment. A tool you complete and bring sits top; organisations that list specific, checkable signs come next; general explanation follows. It is not a ranking of authority — all of these are official bodies or their equivalent.
Why do the sources use different measures?
They're different windows on the same thing. Volume has long been the clinical measure; pages written for patients lead with signs and duration, which you can check without measuring anything. They don't contradict each other, and looking at two or three together describes your situation better than any one alone.
Why seven?
Because seven were open and readable on 4 August 2026. Pages that wouldn't load, or whose content couldn't be confirmed, were left out rather than listed on reputation.
Can this diagnose anything?
No. This is a record of what each organisation publishes, and it is not medical advice. Every source here says the same thing: if you're worried, speak to a doctor. In Australia, healthdirect's nurse line is 1800 022 222.
If you are weighing up which app to keep the record in, the companion piece compares six alternatives to Flo and Clue — ratings, last update dates and privacy scores in one table.
What is the board?
This list exists as a real, public SaveBoard board, so reading it and keeping it are the same action. Open it as-is, or copy it into your own account and add your own clinic or the material you find.