Heavy periods: what counts as heavy and what helps
Your periods count as heavy if you soak through a pad or tampon every one to two hours, need to double up products, bleed for more than 7 days, pass clots bigger than about 2.5 cm (a quarter), flood through to clothes or bedding, or the bleeding disrupts your life. Heavy periods are common, often treatable, and can cause low iron, so they're worth raising with a doctor.
How to tell if your periods are heavy
Most people don't know how much is "normal", because nobody measures. Doctors define heavy menstrual bleeding as bleeding that's heavy enough to affect your physical, emotional or social life. In practice, these signs are the ones to look for:
- Soaking through one or more pads or tampons every hour or two, for several hours in a row
- Needing to wear two products at once, like a pad and a tampon
- Needing to change products during the night
- Passing clots larger than about 2.5 cm, roughly the size of a quarter
- Bleeding for more than 7 days
- Bleeding through to clothes or bedding
- Planning your life around your period, or missing work or school because of it
- Feeling tired, breathless or dizzy, which can be signs of anemia
Menstrual cups make measuring easy. Most hold about 25 to 30 ml. Regularly filling a cup in under two hours is a sign of heavy bleeding worth mentioning to a doctor.
What causes heavy periods
For many people, no single cause is found, and heavy periods are simply how their body works. Heavier periods are also common in the first years after periods start, after pregnancy and in perimenopause, when skipped ovulation lets the lining build up more. Conditions that can cause heavy bleeding include:
| Cause | What it is | Other clues |
|---|---|---|
| Fibroids | Non-cancerous growths in or around the uterus | Pressure, needing to pee more, a swollen tummy |
| Adenomyosis | Lining-like tissue growing into the uterine muscle | Very painful periods, a bulky, tender uterus |
| Polyps | Small growths in the uterine lining | Bleeding between periods |
| Endometriosis | Lining-like tissue outside the uterus | Painful periods, pain with sex or bowel movements |
| Hormone changes, PCOS, thyroid | Irregular ovulation lets the lining thicken | Irregular cycles, very long gaps then heavy bleeds |
| Bleeding disorders | Conditions like von Willebrand disease | Heavy periods since your first one, easy bruising, nosebleeds, heavy bleeding after dental work |
| Medicines and devices | Blood thinners, a copper IUD | Started after the medicine or device |
| Rarely, womb cancer or precancer | More likely after 45 or with risk factors | Bleeding between periods or after menopause |
What helps heavy periods
Treatments that work
Heavy periods are very treatable, and you don't need to have a specific cause to get help. Options a doctor may offer include:
- The hormonal IUD (levonorgestrel), recommended as a first-line treatment by NICE, which can make periods much lighter or stop them
- Tranexamic acid, a non-hormonal tablet taken only on heavy days, which helps blood clot in the uterus
- NSAIDs such as ibuprofen or mefenamic acid on heavy days, which reduce both bleeding and pain
- Combined pill or progestogen-only options, which thin the lining
- Treating the cause, such as removing polyps or fibroids
- Procedures like endometrial ablation, or in some cases surgery, when other treatments haven't worked and you don't plan pregnancy
Looking after yourself
- Eat iron-rich foods: red meat, beans, lentils, tofu, dark leafy greens and fortified cereals, with vitamin C to help absorption.
- Ask for a blood test for iron and anemia. Don't start iron tablets without checking with a doctor or pharmacist first.
- Use higher-absorbency products, period underwear or a cup overnight, plus a towel on the bed on your heaviest nights.
- Rest on your heaviest days when you can.
Heavy periods, energy and mood
Heavy bleeding isn't just inconvenient. Losing more iron than you take in can leave you exhausted, foggy, cold and short of breath, and low iron is linked to low mood and poor concentration. Many people only realize how much heavy periods were affecting them once they're treated. If you feel tired all the time, an iron check is a good first step.
See a doctor if your periods are heavy by any of the signs above, if they've become heavier than usual, or if you also have pelvic pain, bleeding between periods or after sex, or symptoms of anemia like tiredness and breathlessness. Get urgent help if you're soaking a pad or tampon every hour for more than two hours, feel faint, dizzy or have a racing heart, or bleed heavily while pregnant. Any bleeding after menopause must be checked.
Frequently asked questions
How much bleeding is too much on a period?
Soaking a pad or tampon every one to two hours, doubling up, bleeding more than 7 days or passing clots bigger than a quarter are signs of heavy bleeding.
Why are my periods suddenly heavier?
Common reasons include perimenopause, coming off hormonal contraception, a copper IUD, fibroids or polyps. A sudden change is worth checking.
Can heavy periods cause anemia?
Yes. Heavy periods are one of the most common causes of iron deficiency anemia, which causes tiredness, breathlessness and pale skin.
Do heavy periods mean something is wrong?
Often not, but they're worth treating either way, and a doctor can check for causes like fibroids or a bleeding disorder.
Sources
- NHS: Heavy periods
- ACOG: Heavy Menstrual Bleeding
- NICE: Heavy menstrual bleeding: assessment and management (NG88)
- Cleveland Clinic: Heavy Menstrual Bleeding (Menorrhagia)
- NHS: Iron deficiency anaemia
This page is for information only and isn鈥檛 medical advice. If something worries you, please talk to a doctor.
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