You’re changing pads far more often than usual, or you’ve bled through to your sheets. A single heavy month is common, and it often follows something you can name. The questions to answer are how heavy it really is, what changed, and whether this is the first heavy period or the latest of several.
How heavy is too heavy for a period?
The NHS says many people have heavy periods and that they can be normal. It counts a period as heavy if any of these apply.
- You need to change your pad or tampon every 1 to 2 hours.
- You need to use two period products at once.
- You bleed through to your clothes or bedding.
- You pass clots larger than about 2.5cm, the size of a 10p coin.
- Your period lasts more than 7 days.
- You avoid things or take time off work because of it, or you feel tired or short of breath a lot.
Cleveland Clinic puts numbers on it. A typical period loses 2 to 3 tablespoons of blood, and a heavy one loses more than 5. It says heavy periods affect 27% to 54% of people who menstruate, so you’re far from alone. The CDC puts it at more than 10 million American women a year.
Why is my period so heavy this month?
When one period is much heavier than your others, look first at what changed in the last few months.
- You stopped hormonal birth control. The pill keeps the womb lining thin, so periods after it are often heavier than the bleeds you had on it. The guide to periods after stopping birth control has the timings.
- You got a copper IUD. The NHS says it can make periods heavier, longer or more painful, and that this may improve after a few months. The IUD guide covers what to track.
- You had a baby. Periods may not come back the same as before. Our guide to your period after giving birth says when heavier bleeding needs a call.
- You’re in your 40s. Periods often get heavier in perimenopause, and Cleveland Clinic names anovulation, a cycle where you don’t release an egg, as a cause. The perimenopause guide goes through it.
- You could be pregnant. Cleveland Clinic lists miscarriage and ectopic pregnancy among the causes of heavy bleeding. A heavy period that also came late is worth a pregnancy test.
- You started a new medicine. The NHS and Cleveland Clinic both name blood thinners.
Thyroid problems and PCOS can also change your flow from month to month. Cleveland Clinic lists both.
Heavy periods that keep happening
If your periods have been heavy for months and nothing above fits, the cause is often in the womb itself. The NHS and Cleveland Clinic both list fibroids, polyps, endometriosis and adenomyosis. Fibroids and polyps are growths that are usually not cancer.
Bleeding disorders are the other big group, and they’re easy to miss. The CDC names von Willebrand disease first. It says that if a gynaecologist finds no cause for heavy periods, you should be tested for a bleeding disorder. The NHS adds that, rarely, heavy periods can be a sign of womb cancer, which is one more reason not to wait if they’ve changed.
Heavy period with clots
Small clots are common on your heaviest days. Size is what doctors ask about. The NHS line is about 2.5cm, the size of a 10p coin, and the CDC uses the size of a quarter. Clots that big are a sign of heavy bleeding, not a diagnosis. Note how often you pass them and how big they are, and bring that to the appointment.
Heavy and painful periods
Heavy bleeding with bad pain points towards fibroids, endometriosis or adenomyosis. The NHS says to see a GP if you have severe pain during your period, or heavy periods along with pain when peeing, pooing or having sex. Our guide to tracking periods with endometriosis shows what to log before that appointment.
When a heavy period needs help today
Most heavy periods can wait for a normal appointment. These can’t.
- You bleed through two or more pads or tampons an hour for two to three hours in a row. Cleveland Clinic says to see a provider or get emergency care.
- You feel faint, dizzy or very short of breath.
- You could be pregnant and you’re soaking a pad soon after putting it on, or you have severe tummy or shoulder pain. The NHS says to call 999.
When to see a GP about heavy periods
The NHS says to see a GP if heavy periods are affecting your life, if they’ve gone on for some time, or if you bleed between periods or after sex. Feeling tired all the time counts too. Cleveland Clinic says heavy bleeding can lead to anaemia, and a blood test checks for it.
There’s a lot a GP can do. The NHS lists tranexamic acid, a medicine that reduces bleeding, and the hormonal coil (IUS), along with other options. A record of your last few periods helps them choose. Write down how many days each lasted, how often you changed products on the worst day, and any clots. A period diary or an app keeps that for you. If the bleeding went on past a week, the guide to a period lasting too long covers that side, and the guide to a light period covers the opposite change.
How Plum tracks a heavy period
We make Plum, a period tracker app for iPhone, so this part is about our own app. You can log each period day as light, medium or heavy, and spotting separately. Each cycle’s summary in Insights shows the flow you logged, a drop for every day, and names the day a heavy stretch started.
That gives you the answer to a doctor’s first question, which is whether this period is different from your usual ones. Put a few cycles side by side and you can see it. Plum shows no ads and never sells personal data.
