Many people with heavy periods assume that what they have is normal, simply because it is what they have always had. But bleeding that floods through protection, keeps you home or leaves you exhausted is not something you have to put up with. Heavy menstrual bleeding is common, it often has a treatable cause, and there are several effective treatments.
This guide explains what counts as heavy, the most common causes, the link with low iron, how doctors look into it and the treatment options, from tablets to procedures.
What Counts as a Heavy Period?
The medical name is menorrhagia, or heavy menstrual bleeding. Doctors no longer rely on measuring blood loss, which is hard to do at home. The NICE guideline on heavy menstrual bleeding defines it as bleeding heavy enough to interfere with your physical, social, emotional or working life. In practice, your periods may be heavy if you:
- Need to change a pad or tampon every 1 to 2 hours, or empty a menstrual cup more often than its instructions suggest
- Have to use two types of protection at once, such as a tampon and a pad
- Pass blood clots larger than about 2.5 cm (roughly the size of a 10p or a US quarter)
- Bleed for more than 7 days
- Bleed through to your clothes or bedding, or need to get up at night to change protection
- Plan your day around being near a toilet, or miss work, school or plans
- Feel tired, short of breath or dizzy around your period
Not sure if your bleeding is different from spotting? Our guide to spotting before periods explains how to tell them apart.
Common Causes of Heavy Periods
For a lot of people, no specific cause is found, and the bleeding is linked to how the womb lining itself works. When there is a cause, it is usually one of these:
Problems in the womb
- Fibroids: non-cancerous growths in or on the wall of the womb. They are very common and are a frequent cause of heavy, prolonged bleeding.
- Polyps: small growths on the womb lining or cervix, which can also cause bleeding between periods.
- Adenomyosis: tissue like the womb lining grows into the muscle wall, often causing heavy and painful periods.
- Endometriosis: tissue similar to the womb lining grows outside the womb. It is better known for pain, but can make periods heavier. We cover its wider effects in our article on endometriosis and mental health.
Hormonal and medical causes
- Irregular ovulation, common in the teenage years, around perimenopause and with PCOS. When you do not ovulate regularly, the lining can build up and then shed heavily.
- Thyroid problems, especially an underactive thyroid.
- Bleeding disorders such as von Willebrand disease. This is worth considering if your periods have been heavy since your first one, or you also bruise easily, have nosebleeds or bleed a lot after dental work or childbirth.
- Medicines such as blood thinners (anticoagulants).
- The copper coil (IUD), which often makes periods heavier, especially in the first months.
Less common but important
Pelvic infection and, rarely, womb (endometrial) cancer or precancerous changes in the lining can cause heavy or irregular bleeding. The risk is higher after 45, with obesity and with PCOS. This is why new changes in your bleeding pattern, bleeding between periods or any bleeding after menopause should always be checked.
Heavy Periods and Iron Deficiency Anaemia
Losing more blood each month than your diet can replace slowly drains your iron stores. Heavy periods are one of the most common causes of iron deficiency anaemia in people who menstruate. Signs include:
- Tiredness and low energy that rest does not fix
- Shortness of breath or a racing heart on stairs
- Pale skin, headaches and feeling cold
- Hair shedding, brittle nails or cravings to chew ice
A simple blood test (full blood count, and sometimes ferritin) can check this. If you are low, your doctor may suggest iron tablets alongside treatment for the bleeding itself. Do not start high-dose iron without a test, as too much iron can cause problems. If you are often drained in the afternoon, our piece on afternoon energy crashes looks at other everyday causes too.
How Doctors Find the Cause
Your doctor will start by asking about your periods, symptoms and medical history. It helps to bring notes. Depending on your age and symptoms, tests may include:
- Blood tests for anaemia, and sometimes thyroid function or clotting tests
- A pelvic examination, and a cervical screening test if one is due
- A pelvic ultrasound, usually transvaginal, to look for fibroids, polyps or adenomyosis
- Hysteroscopy, a thin camera passed through the cervix to look inside the womb, sometimes with a small sample (biopsy) of the lining
- A pregnancy test, since unexpected heavy bleeding can be a sign of early pregnancy loss
Treatment Options
Treatment depends on the cause, how much the bleeding affects you and your plans for future pregnancy. Many people try a medicine first. The American College of Obstetricians and Gynecologists and NICE describe a similar range of options.
| Treatment | How it helps | Good to know |
|---|---|---|
| Hormonal IUS (levonorgestrel coil) | Thins the womb lining; many users bleed much less or stop | NICE recommends it first for many people; also contraception; irregular spotting is common at first |
| Tranexamic acid | Helps blood clot in the womb, reducing flow | Taken only on heavy days; not hormonal; not suitable with some clotting risks |
| NSAIDs (ibuprofen, mefenamic acid) | Lower the substances that drive bleeding and cramps | Taken during the period; reduce pain too; avoid with stomach ulcers or some kidney problems |
| Combined pill, patch or ring | Regulate cycles and thin the lining | Also contraception; not for everyone, such as some smokers over 35 |
| Progestogen tablets or injection | Thin the lining or reduce bleeding | Can cause irregular bleeding or mood changes |
Procedures and surgery
If medicines do not help, are not suitable, or there is a structural cause, other options include:
- Removal of polyps during hysteroscopy, often a short procedure.
- Fibroid treatments, such as medicines to shrink them, removing fibroids (myomectomy) or blocking their blood supply (uterine artery embolisation).
- Endometrial ablation, which destroys the womb lining. It can reduce or stop periods, but it is only for people who do not want any future pregnancies.
- Hysterectomy, removal of the womb. It ends periods permanently and is usually considered after other options, as it is major surgery.
Tracking Your Periods
A simple record makes your appointment more useful and helps you see whether treatment is working. For two or three cycles, note:
- The start and end date of each period
- How many pads or tampons you use each day, and what absorbency
- Any clots and their rough size
- Night-time leaking or changes
- Pain, tiredness and days of missed activities
A period tracking app or a notes page on your phone both work. Period pants and high-capacity menstrual cups can help day to day, but they manage symptoms rather than treat the cause.
Related reading: Ectopic Pregnancy: Symptoms, Treatment and Recovery.
FAQ
How much bleeding is too much during a period?
If you change protection every 1 to 2 hours, double up on products, pass clots larger than about 2.5 cm or bleed for more than 7 days, your periods are heavy and worth discussing with a doctor.
Are blood clots in period blood normal?
Small clots are common, especially on heavy days. Frequent clots larger than about 2.5 cm suggest heavy bleeding and should be checked.
Can heavy periods be a sign of cancer?
Rarely. Most heavy periods are caused by benign conditions such as fibroids or hormonal changes. New changes, bleeding between periods and bleeding after menopause need checking, particularly over 45.
Why are my periods suddenly heavier in my 40s?
During perimenopause, ovulation becomes irregular and the lining can build up more, leading to heavier or longer periods. Fibroids and polyps also become more common, so it is still worth a check.
Does ibuprofen reduce period bleeding?
Yes, NSAIDs such as ibuprofen can reduce flow as well as cramps when taken regularly during your period. Follow the label and check with a pharmacist if you have stomach, kidney or asthma problems. For pain that feels unusual, see our guide to lower abdominal pain.
The Bottom Line
Heavy periods are common, but they are not something to quietly put up with. Bleeding that soaks through protection, lasts more than a week or leaves you tired and breathless deserves a check, including a blood test for anaemia. Most causes are benign and treatable, and options range from tablets you take only on heavy days to a hormonal coil and, if needed, procedures. Find more guides in our women’s health hub.
This article is for general information and is not a substitute for advice from your doctor.
Sources
- NHS: Heavy Periods
- NICE: Heavy Menstrual Bleeding: Assessment and Management (NG88)
- ACOG: Heavy Menstrual Bleeding
- Cleveland Clinic: Menorrhagia (Heavy Menstrual Bleeding)
- MedlinePlus: Bleeding Disorders
Medical disclaimer: This article is for general information only and is not a substitute for advice, diagnosis or treatment from a qualified health professional. If your symptoms are severe, sudden or getting worse, contact a doctor or emergency services.
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