Some women lose an excessive amount of blood during their period.
The medical term for heavy periods is "menorrhagia". It can sometimes happen along with other symptoms, such as period pain.
Heavy bleeding doesn't necessarily mean there's anything seriously wrong, but it can affect a woman physically and emotionally, and disrupt everyday life.
See your GP if you're worried about heavy bleeding during or between your periods.
This page covers:
How much is heavy bleeding?
It's difficult to define exactly what a heavy period is because this varies from woman to woman. What's heavy for one woman may be normal for another.
The average amount of blood lost during a period is 30 to 40 millilitres (ml), with 9 out of 10 women losing less than 80ml. Heavy menstrual bleeding is considered to be 60ml or more in each cycle.
But it's not usually necessary to measure blood loss. Most women have a good idea of how much bleeding is normal for them during their period, and can tell when this amount increases or decreases.
A good indication that your blood loss is excessive is if:
- you feel you're using an unusually high number of tampons or pads
- you experience flooding (heavy bleeding) through to your clothes or bedding
- you need to use tampons and towels together
What causes heavy periods?
In some cases, the cause of heavy periods can't be identified. But there are a number of conditions and some treatments that can cause heavy menstrual bleeding.
Conditions that can cause heavy bleeding include:
- polycystic ovary syndrome (PCOS) - a common condition that affects how the ovaries work; it causes irregular periods, and periods can be heavy when they start again
- pelvic inflammatory disease (PID) - an infection in the upper genital tract (the womb, fallopian tubes or ovaries) that can cause pelvic or abdominal pain and bleeding after sex or between periods
- fibroids - non-cancerous growths that develop in or around the womb and can cause heavy or painful periods
- adenomyosis - when tissue from the womb lining becomes embedded in the wall of the womb
- endometriosis - when small pieces of the womb lining are found outside the womb, such as in the fallopian tubes, ovaries, bladder or vagina (although this is more likely to cause painful periods)
- an underactive thyroid gland (hypothyroidism) - where the thyroid gland doesn't produce enough hormones, causing tiredness, weight gain and feelings of depression
- cervical or endometrial polyps - non-cancerous growths in the lining of the womb or cervix (neck of the womb)
- blood clotting disorders, such as Von Willebrand disease
- cancer of the womb (although this is relatively rare)
Medical treatments that can sometimes cause heavy periods include:
Diagnosing heavy periods
Your GP will usually investigate heavy periods by carrying out a pelvic examination.
If an underlying cause of your heavy periods isn't found, you may have an ultrasound scan.
Read more about diagnosing heavy periods.
Treating heavy periods
You may not need treatment if a serious cause isn't suspected, or the bleeding doesn't affect your everyday life.
If treatment is necessary, medication is usually tried first. But it may take a while to find a medication that's effective and suitable for you.
Some treatments also act as contraception.
If medication doesn't work, surgery may be a possible treatment option.
Read more about treating heavy periods.
Bleeding after childbirth
After having a baby, heavy vaginal bleeding, known as lochia, is very common and completely normal. It's your body's way of getting rid of the womb lining after you've given birth.
The bleeding can last from two to six weeks, and the blood may come out quickly, or slowly and evenly.
The amount of blood loss varies between women. If you've had a caesarean section, you'll also have some bleeding as the womb lining sheds, although it may be lighter than if you'd had a vaginal birth.
You'll need to use thick sanitary pads to start with while the bleeding is at its heaviest.
Once the flow settles down, you can switch to using normal sanitary pads. Always wash your hands before and after changing your pad.
Don't use tampons for the first six weeks after the birth as it increases the risk of your womb becoming infected.
The colour of the blood will also change in the days and weeks after childbirth. It'll be bright red for the first few days and may contain small clots.
As the bleeding becomes less heavy, the colour of the blood will lighten, becoming pinkish and more watery.
It's important to make sure you get plenty of rest and don't overdo it during this time.
You should seek medical advice from your GP or midwife if:
- the bleeding smells unpleasant
- you get a fever or chills
- you still have heavy, bright red bleeding after the first week
- you have lower tummy pain on one or both sides
Dial 999 to ask for an ambulance if you experience very heavy bleeding (bleeding that soaks through more than one pad an hour) after having a baby.
It could be a postpartum haemorrhage caused by a piece of placenta still inside your womb. You may need antibiotics or an operation to remove the piece of placenta.
Visit your GP if you feel your periods are unusually heavy. They'll investigate the problem and may offer treatments to help.
To try to find out what's causing your heavy periods, your GP will ask about:
- your medical history
- the nature of your bleeding
- any related symptoms you have
They'll also ask some questions about your periods, including:
- how many days your periods usually last
- how much bleeding you have
- how often you have to change your tampons or sanitary pads
- whether you experience flooding (heavy bleeding through to your clothes or bedding)
- what impact your heavy periods are having on your everyday life
- whether you bleed between periods or after sex
- whether you also have pelvic pain
To help determine the cause of your heavy bleeding, you may have a physical examination, particularly if you have pelvic pain or bleeding between periods or after sex.
You'll also be asked about your family history to rule out inherited conditions that may be responsible, such as Von Willebrand disease, which runs in families and affects the blood's ability to clot.
Depending on your medical history and the results of your physical examination, the cause of your heavy bleeding may need to be investigated further.
For example, if you have pelvic pain and experience bleeding between periods or during or after sex, you'll need further tests to rule out serious illness, such as womb cancer (a rare cause of heavy menstrual bleeding).
If you need to have a pelvic examination, your GP will ask if you'd like a female assistant to be present.
A pelvic examination will include:
- a vulval examination - an examination of your genitals for evidence of external bleeding and signs of infection, such as a vaginal discharge
- a speculum examination - a speculum is a medical instrument inserted into your vagina to allow your vagina and cervix to be examined
- bimanual palpation - fingers are used to examine the inside of your vagina to identify whether your womb or ovaries are tender or enlarged
Before carrying out a pelvic examination, your GP or gynaecologist will explain the procedure to you and why it's necessary.
You should ask about anything you're unsure about. A pelvic examination shouldn't be carried out without your consent.
In some cases of heavy bleeding, a biopsy may be needed to establish a cause. This will be carried out by a specialist and involves removing a small sample of womb lining for closer examination under a microscope.
If you have iron deficiency anaemia, you'll usually be prescribed a course of medication.
Your GP will be able to advise you about the type of medication most suitable for you and how long you need to take it for.
If the cause of your heavy menstrual bleeding is still unknown after you've had the above tests, you may need an ultrasound scan of your womb.
This looks for abnormalities such as non-cancerous growths (fibroids) or harmless growths (polyps). It can also be used to detect some types of cancer.
A transvaginal ultrasound scan is often used. A small probe is inserted into your vagina to get a close-up image of your womb.
You may not need treatment for heavy periods if there isn't a serious cause or if the bleeding doesn't bother you.
Bleeding can vary over time for some women, so it may simply be that your bleeding is currently heavier than usual.
If you do need treatment, the aim is to:
- reduce or stop excessive menstrual bleeding
- treat or prevent iron deficiency anaemia caused by heavy bleeding
The various treatments for heavy periods are outlined below.
You can also read a summary of the pros and cons of the treatments for heavy periods, allowing you to compare your treatment options.
Medication is usually tried first. If a particular medication isn't effective or suitable for you, another type may be recommended.
Some medications make your periods lighter and others may stop bleeding completely. Some are also contraceptives.
Your GP will explain how each type of medication works and any possible side effects. This will help you decide which treatment is most suitable.
The different types of medication used to treat heavy periods are outlined below.
Levonorgestrel-releasing intrauterine system (LNG-IUS)
The levonorgestrel-releasing intrauterine system (LNG-IUS) is a small plastic device inserted into your womb. It slowly releases a hormone called progestogen.
It prevents the lining of your womb growing quickly and is also a form of contraceptive. LNG-IUS doesn't affect your chances of getting pregnant after you stop using it.
Possible side effects of using LNG-IUS include:
- irregular bleeding that may last more than six months
- breast tenderness
- stopped or missed periods
LNG-IUS has been shown to reduce bleeding by more than 90% and it's usually the preferred treatment to try first for women with heavy menstrual bleeding.
If LNG-IUS is unsuitable - for example, if contraception isn't wanted - tranexamic acid tablets may be considered.
The tablets work by helping the blood in your womb to clot. They've been shown to reduce blood loss by around 50%.
Two or three tranexamic acid tablets are taken three times a day for a maximum of three to four days.
Treatment should be stopped if your symptoms haven't improved within three months.
Tranexamic acid tablets aren't a form of contraception and won't affect your chances of becoming pregnant. If necessary, tranexamic acid can be combined with a non-steroidal anti-inflammatory drug (NSAID).
Non-steroidal anti-inflammatory drugs (NSAIDs)
Non-steroidal anti-inflammatory drugs (NSAIDs) may also be used to treat heavy periods if LNG-IUS isn't appropriate.
NSAIDs have been shown to reduce blood flow by 20-50%. They're taken in tablet form from the start of your period or just before until heavy bleeding has stopped.
The NSAIDs recommended for treating menorrhagia are:
Naproxen is usually taken twice a day, and ibuprofen and mefenamic acid are usually taken three times a day.
NSAIDs work by reducing your body's production of a hormone-like substance called prostaglandin, which is linked to heavy periods. NSAIDs can also help relieve period pain. They're not a form of contraceptive.
You can keep taking NSAIDs for as long as you need to if they're reducing blood loss and not causing significant side effects. But treatment should be stopped after three months if NSAIDs are not effective.
Combined oral contraceptive pill
The combined contraceptive pill, often referred to as "the pill", can be used to treat heavy periods. It contains the hormones oestrogen and progestogen.
You take one pill every day for 21 days before stopping for seven days. During this seven-day break you get your period. This cycle is then repeated.
The benefit of using combined oral contraceptives as a treatment for heavy periods is they offer a more readily reversible form of contraception than LNG-IUS.
They reduce heavy bleeding by around 40% and have the benefit of regulating your menstrual cycle and reducing period pain.
The pill works by preventing your ovaries releasing an egg each month. As long as you're taking it correctly, it should prevent pregnancy.
Common side effects of the combined oral contraceptive pill include:
- mood changes
- nausea (feeling sick)
- fluid retention
- breast tenderness
Norethisterone is a type of man-made progestogen (one of the female sex hormones).
It can be used to treat heavy periods, and is taken in tablet form two to three times a day from days 5 to 26 of your menstrual cycle, counting the first day of your period as day one.
Oral norethisterone works by preventing your womb lining growing quickly. It isn't suitable if you're trying to conceive because it's likely to inhibit ovulation.
It can reduce heavy bleeding by more than 80%, but isn't an effective form of contraception and can have unpleasant side effects, including:
- weight gain
- breast tenderness
- short-term acne
Oral progestogens, such as norethisterone, aren't as effective as tranexamic acid and may not always be able to control heavy bleeding.
A type of progestogen called medroxyprogesterone acetate is also available as an injection and is sometimes used to treat heavy periods.
It prevents the lining of your womb growing quickly and reduces bleeding by up to 50%. It's also a form of contraception.
Injected progestogen doesn't prevent you becoming pregnant after you stop using it, although there may be a delay of 6 to 12 months after stopping before you're able to get pregnant.
Common side effects of injected progestogen include:
- weight gain
- irregular bleeding
- stopped or missed periods
- premenstrual symptoms, such as bloating, fluid retention and breast tenderness
You'll need to have progestogen injected once every 12 weeks for as long as treatment is required.
Gonadotropin releasing hormone analogue
Gonadotropin releasing hormone analogue (GnRH-a) is a hormone sometimes given as an injection to treat fibroids (non-cancerous growths in the womb).
Studies have shown GnRH-a is effective in reducing blood loss during periods by almost 90%.
This means GnRH-a isn't a routine treatment, but may be used while you await surgery.
Your specialist may suggest surgery if medication isn't effective in treating your heavy periods.
If the cause is fibroids, you may be recommended either:
- uterine artery embolization
If your heavy periods aren't caused by fibroids, your options include:
- endometrial ablation - where the womb lining is destroyed
- hysterectomy - surgical removal of the womb
Your specialist can discuss these procedures with you, including the benefits and any associated risks.
Uterine artery embolisation (UAE)
Uterine artery embolisation (UAE) involves inserting a small tube into your groin.
Small plastic beads are injected through the tube into the arteries supplying blood to the fibroid. This blocks the arteries and causes the fibroid to shrink over the following six months.
Advantages of UAE include:
- it's usually effective in treating heavy periods caused by fibroids
- serious complications are rare
- you only need to spend one night in hospital
But having UAE may cause some pain after the blood supply is removed, and strong painkillers are needed for about eight hours. There are also other complications your specialist will be able to discuss with you.
If you plan to get pregnant in the future, you may choose not to have UAE, as there are potential risks to your fertility.
In around 10-20% of cases, UAE may be required again later on. Your specialist will discuss this with you.
Sometimes fibroids can be removed using a surgical procedure called a myomectomy. But it isn't suitable for every type of fibroid.
Your specialist will be able to tell you whether a myomectomy is possible and what the possible complications are.
When they're appropriate, myomectomies are effective. But in some cases the fibroids grow back.
Read more about treating fibroids.
Different techniques can be used for endometrial ablation.
- microwave endometrial ablation - a probe that uses microwave energy (a type of radiation) is inserted into the womb to heat and destroy the womb lining
- thermal balloon ablation - a balloon is inserted into your womb and inflated and heated to destroy the womb lining
You may experience some vaginal bleeding for a few days after endometrial ablation, similar to a light period.
Use sanitary towels rather than tampons. Some women can have bloody discharge for three or four weeks.
Some women have reported experiencing more severe or prolonged pain after having endometrial ablation.
In this case, you should speak to your GP or a member of your hospital care team who may be able to prescribe a stronger painkiller.
It's usually recommended that you don't get pregnant after having endometrial ablation because the risk of problems, such as miscarriage, is high.
The failure rate for endometrial ablation is about 25-35%. If it fails, you may be offered a repeat treatment.
For further information, the (RCOG) have produced a leaflet called Information for you after an endometrial ablation (PDF, 1.05Mb).
A hysterectomy (removal of the womb) will stop any future periods, but should only be considered after other options have been tried or discussed.
The operation and recovery time are longer than for other surgical techniques for treating heavy periods.
A hysterectomy is only used to treat heavy periods after a thorough discussion with your specialist to outline the benefits and disadvantages of the procedure.
You won't be able to get pregnant after having a hysterectomy.