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Page last reviewed: 13/07/2011

Heavy periods, also called menorrhagia, are when a woman loses an excessive amount of blood during several consecutive periods.

A period is part of a woman's menstrual cycle. The menstrual cycle is the time from the first day of a woman's period to the day before her next period. A period is a bleed from the womb (uterus) that is released through the vagina. It happens approximately every 28 days, although anywhere between 24 and 35 days is common.

Periods can begin when girls are between eight and 16 years of age, but they usually start around 12 years of age. They continue every month until the menopause (when a woman's periods stop), which usually occurs between 45 and 55 years of age.


Menorrhagia is the medical name for heavy periods. Menorrhagia can occur by itself or in combination with other symptoms, such as menstrual pain (dysmenorrhoea).

Heavy bleeding does not necessarily mean there is anything seriously wrong, but it can affect a woman physically, emotionally and socially, and can cause disruption to everyday life. 

How much is heavy bleeding?

It is difficult to define exactly what a heavy period is because the amount of blood that is lost during a period can vary considerably between women.

Heavy menstrual bleeding is considered to be 60-80ml (millilitres) or more in each cycle. The average amount of blood that is lost during a period is 30-40ml, with 9 out of 10 women losing less than 80ml. However, it is rarely necessary in clinical practice to measure the blood loss so accurately.

Most women have a good idea about how much bleeding is normal for them during their period and can tell when this amount increases or decreases.

Visit your GP if your periods are heavier than usual, or if they are disrupting everyday life. A good indication that your blood loss is excessive is if:

  • you feel that you are 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

How common are heavy periods?

It is difficult to measure exactly how many women have heavy periods. This is because different women have different ideas of what 'heavy' bleeding is. However, some estimates suggest that one woman in ten has heavy periods. 


There are several different medications that can be used to treat heavy periods. Surgery may also be an option. See Heavy periods - treatment for more information.

The uterus (or womb) is a hollow, pear-shaped organ in a woman where a baby grows during pregnancy.

The vagina is a tube of muscle that runs from the cervix (the opening of the womb) to the vulva (the external sexual organs).

Page last reviewed: 13/07/2011

There is no underlying cause in 40-60% of cases of heavy periods (menorrhagia). 

Otherwise, possible causes of heavy periods include the following:

  • cervical or endometrial polyps: these are non-cancerous growths in the womb or the lining of the cervix (neck of the womb) 
  • endometriosis: this is a condition where the tissue lining the womb (endometrium) is found in places outside the uterus, usually in the pelvis.
  • uterine fibroids: these are non-cancerous growths in the womb that can cause pelvic pain
  • intrauterine contraceptive devices (IUD), also known as 'the coil': blood loss may increase by 40-50% after an IUD is inserted
  • pelvic inflammatory disease (PID): this is an ongoing infection in the pelvis that can cause pelvic pain, fever and bleeding after sexual intercourse or between periods
  • polycystic ovary syndrome (PCOS): women with PCOS typically have a number of cysts in their ovaries
  • blood clotting disorders such as von Willebrand disease
  • an underactive thyroid gland (hypothyroidism): this may cause fatigue, constipation, intolerance to cold and hair and skin changes
  • liver or kidney disease
  • cancer of the womb (although this is very rare)

Treatments that can cause heavy periods

Heavy periods may sometimes be caused by medical treatments. These can include:

  • anticoagulant medicines (medication to reduce the ability of the blood to clot) 
  • chemotherapy (cancer treatment)
Fallopian tubes
The tubes connecting the ovaries to the womb.
The pair of reproductive organs that produce eggs and sex hormones in females.
Thyroid gland
The thyroid gland is found in the neck and produces hormones that control the body's growth and metabolism.
The vagina is a tube of muscle that runs from the cervix (the opening of the womb) to the vulva (the external sexual organs).
The womb (or uterus) is a hollow, pear-shaped organ in a woman where a baby grows during pregnancy.

Page last reviewed: 13/07/2011

Visit your GP if you feel that your periods are unusually heavy. Your GP will be able to investigate the problem and offer treatments to help.

Heavy periods (menorrhagia) are diagnosed when both you and your GP agree that your menstrual bleeding is heavy, after details about your periods and medical history have been taken.

Medical history

To establish the cause of your heavy periods, your GP will ask you some questions about:

  • your medical history
  • the nature of your bleeding
  • any related symptoms that you have

Your GP will ask you about your periods. They may ask:

  • how many days your periods usually last
  • how much bleeding you have
  • how often you have to change your tampons or sanitary pads
  • whether or not you experience flooding (heavy bleeding through to your clothes or bedding) 
  • what impact your heavy periods are having on your everyday life

Your GP will also ask you whether you have any bleeding between periods (inter-menstrual bleeding) or after sexual intercourse (post-coital bleeding), and whether you experience any 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. Your doctor may need to do a vaginal examination which could include passing a speculum to look at your cervix and possibly to do a cervical smear.

You may be asked about the contraception that you currently use, whether you are considering changing it and whether you have any future plans to have a baby. The last time you had a cervical screening test (cervical smear) will also be noted.

Finally, your GP may also ask you about your family history to determine whether it is possible that an inherited condition may be responsible for your heavy bleeding. For example, von Willebrand disease, which can run in families, is a coagulation disorder that affects the blood's ability to clot properly.

Further testing

Depending on your medical history and the results of your initial physical examination, the cause of your heavy bleeding may need to be investigated further. For example, if you experience inter-menstrual or post-coital bleeding, or you have pelvic pain, you will need to have some further tests to rule out serious illness, such as an underlying cancer (which is very rare).

If you need to have a pelvic examination, your GP will ask for a female assistant to be present at the time. A pelvic examination will include:

  • a vulval examination: an examination of your vulva (external sexual organs) for evidence of external bleeding and signs of infection, such as a vaginal discharge
  • a speculum examination of your vagina and cervix (neck of the womb): a speculum is a medical instrument that is used for examining the vagina and cervix
  • bimanual palpation: an internal examination of your vagina using the fingers to identify whether your womb or ovaries are tender or enlarged

Pelvic examinations should only be carried out by healthcare professionals who are qualified to perform them, such as a GP or gynaecologist (a specialist in the female reproductive system).

Before carrying out a pelvic examination, the healthcare professional will explain the procedure to you and the reasons why it is necessary. You should ask about anything that you are unsure about. A pelvic examination should not be carried out without your consent (permission). 

In some menorrhagia cases, a biopsy may be needed to establish a cause. This will be carried out by a specialist and involves removing a small sample of your womb lining for closer examination under a microscope.

Blood tests

A full blood count is usually carried out for all women who have heavy periods. This can detect iron-deficiency anaemia, which is often caused by a loss of iron following prolonged heavy periods.

If you have iron-deficiency anaemia, you will usually be prescribed a course of medication. Your GP will be able to advise you about the type of medication that is most suitable for you and how long you need to take it for.

See the Health A-Z topic about Iron deficiency anaemia for more information.

Ultrasound scan

If you have heavy menstrual bleeding and the cause is still unknown after you've had tests, an ultrasound examination of your womb may be used to look for abnormalities, such as fibroids (non-cancerous growths) or polyps (harmless growths). Ultrasound can also be used to detect some forms of cancer.

A trans-vaginal scan is often used, which involves a small probe being inserted into the vagina to take a close-up image of your womb.

See the Health A-Z topic about Ultrasound scans for more information.

The pair of reproductive organs that produce eggs and sex hormones in females.
The vagina is a tube of muscle that runs from the cervix (the opening of the womb) to the vulva (the external sexual organs).
The womb (or uterus) is a hollow, pear-shaped organ in a woman where a baby grows during pregnancy.

Page last reviewed: 13/07/2011

As the amount of blood that is lost during a woman's period varies considerably from one person to another, menorrhagia (heavy periods) is not always diagnosed.

If menorrhagia is diagnosed, your GP will discuss all the possible treatment options with you. Your GP will inform you about:

  • the effectiveness of treatments
  • the likelihood of any adverse effects following treatments
  • whether contraception will be required
  • the implications of treatment on fertility

The aims of treating menorrhagia are:

  • to reduce or stop excessive menstrual bleeding
  • to prevent or correct iron-deficiency anaemia caused by heavy menstrual bleeding
  • to use surgical treatments for women who may benefit from them 
  • to improve the quality of life of women with heavy menstrual bleeding


Medication is recommended as the first type of treatment for use in cases of menorrhagia for women who:

  • have no symptoms or signs that suggest a serious underlying cause
  • are waiting for the results of further investigations

If a particular medication is not suitable for you, or if you try a medication and it is ineffective, another one may be recommended. Some medications make your periods lighter and others may stop bleeding completely. Some medications are also contraceptives. Your GP will explain how each type of medication works and any possible side effects. This will help you and your GP decide which is the most suitable treatment.

The different types of medication that are used to treat menorrhagia are outlined below.

Levonorgestrel-releasing intrauterine system (LNG-IUS) (Mirena)

The levonorgestrel-releasing intrauterine system (LNG-IUS), commonly known as Mirena, is a small plastic device that is placed in your womb and slowly releases a hormone called progestogen. It prevents the lining of your womb from growing quickly and it is also a form of contraceptive. Mirena does not affect your chances of getting pregnant after you stop using it.

Possible side effects of using Mirena include:

  • irregular bleeding that may last for more than six months
  • breast tenderness
  • acne
  • headaches (although they tend to be minor and short-lived)
  • no periods at all (amenorrhoea)

Mirena has been shown to reduce blood loss by 71-96% and is the preferred first choice treatment for women with menorrhagia, provided that long-term contraception using an intrauterine device is appropriate (it is usually used for a minimum of 12 months).

Tranexamic acid

If Mirena is unsuitable (for example, if contraception is not desired), tranexamic acid (Cycklokapron) tablets may be considered. The tablets work by helping the blood in your womb to clot. They have been shown to reduce blood loss by 29-58%.

Two or three tranexamic acid tablets are taken after heavy bleeding has started. They are taken three or four times a day, for a maximum of three to four days. The lower end of this dosing range will usually be recommended. For example, two tablets, three times a day for a maximum of 5 days. Treatment should be stopped if your symptoms have not improved within three months.

Tranexamic acid tablets are not a form of contraception and will not affect your chances of becoming pregnant. If necessary, tranexamic acid can be combined with a non-steroidal anti-inflammatory drug (NSAID) (see below).

Possible side effects include:

  • indigestion
  • diarrhoea
  • headaches (although this is uncommon)

Non-steroidal anti-inflammatory drugs (NSAIDs)

Non-steroidal anti-inflammatory drugs (NSAIDs) may also be used to treat menorrhagia as a second choice treatment if LNG-IUS is not appropriate. NSAIDs have been shown to reduce blood loss by 20-49%. They are taken in tablet form from the start of your period (or just before) and until bleeding has stopped. As with tranexamic acid, treatment should be stopped if your symptoms have not improved within three months.

The NSAIDs that are recommended for treating menorrhagia are:

  • mefenamic acid  (ponstan)
  • naproxen  (naprosyn)
  • ibuprofen  (brufen)
  • diclofenac sodium (difene)

These are usually taken three or four 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 are also painkillers. They are not a form of contraceptive. However, if necessary, they can be used with the combined oral contraceptive pill (see below).

Common side effects of NSAIDs include indigestion and diarrhoea.

NSAIDs can be used for an indefinite number of menstrual cycles, as long as they are relieving symptoms of heavy blood loss and are not causing significant adverse side effects. However, treatment should be stopped after three months if NSAIDs are found to be ineffective.

Combined oral contraceptive pill

Combined oral contraceptive pills, often referred to as the pill, can be used to treat menorrhagia. They contain the hormones oestrogen and progestogen. When you're on the pill 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 menorrhagia is that they offer a more readily reversible form of contraception than LNG-IUS. They also have the benefit of regulating your menstrual cycle and reducing menstrual pain (dysmenorrhoea).

The combined oral contraceptive is a contraceptive that works by preventing your ovaries from releasing an egg each month. As long as you are taking the pills correctly, they should prevent pregnancy.

Common side effects of the combined oral contraceptive pill include:

  • mood changes
  • headaches
  • nausea (feeling sick)
  • fluid retention
  • breast tenderness

See the Health A-Z topic about the Combined contraceptive pill for more information.

One study looked at using gonadotropin releasing hormone analogue (GnRH-a) as well as the combined oral contraceptive pill. It found that women who were treated with both had significantly reduced blood loss compared with women who only used the combined contraceptive pill.

GnRH-a is a type of hormone that is usually used to treat fibroids (non-cancerous growths in the womb). Although more research is needed, GnRH-a may be a possible treatment in the future for women with particularly heavy periods.

Oral norethisterone

Norethisterone is a type of man-made progestogen (one of the female sex hormones). It is another type of medication that can be used to treat menorrhagia. It is taken in tablet form, two to three times a day from days five to 26 of your menstrual cycle, counting the first day of your period as day one.

Oral norethisterone works by preventing your womb lining from growing quickly. It is not an effective form of contraception and can have unpleasant side effects, including:

  • weight gain
  • bloating
  • breast tenderness
  • headaches
  • acne (which does not usually last long)

Oral progestogens, such as norethisterone, are not as effective as tranexamic acid. However, if bleeding is very heavy or has been continuing for a while, a high dose of oral norethisterone can stop bleeding in 24 to 48 hours.

Injected progestogen

A type of progestogen called medroxyprogesterone acetate is also available as an injection and is sometimes used to treat menorrhagia. It works by preventing the lining of your womb from growing quickly, and it is a form of contraception. It does not prevent you becoming pregnant after you stop using it, although there may be a delay after you take it before you are able to get pregnant (see below).

Common side effects of injected progestogen include:

  • weight gain
  • irregular bleeding
  • absence of periods (amenorrhoea)
  • a delay in ability to become pregnant for six to twelve months after stopping the injection
  • premenstrual symptoms, such as bloating, fluid retention and breast tenderness

You will need to have this form of progestogen injected once every twelve weeks, for as long as treatment is required. 


Your specialist may suggest surgery if the above medications are not effective in treating your menorrhagia.

There are several types of operation that can be used to treat menorrhagia. Two are only suitable if your heavy periods are caused by fibroids (non-cancerous growths in the womb). These are:

  • uterine artery embolisation (UAE)
  • myomectomy

Uterine artery embolisation (UAE)

Uterine artery embolisation (UAE) is a minimally invasive procedure that can be carried out through a small tube inserted into your groin. Through this tube, small plastic beads are injected into the arteries supplying blood to the fibroid. This blocks the arteries and causes the fibroid to shrink over the subsequent six months.

People who have UAE may suffer pain after the blood supply is removed, and strong painkillers are needed for about eight hours. There are some other complications that your specialist will be able to tell you about.

The advantage of UAE is that:

  • it is successful in 95% of people who have heavy periods caused by fibroids
  • serious complications are rare
  • you only need to spend one night in hospital
  • your womb and ovaries are not removed, so if you still want children this is possible

Further research needs to be carried out into the success rate of pregnancy after UAE. Sometimes, further embolisations or other procedures are needed after UAE. Your specialist will discuss this with you.


Sometimes, the fibroids can be removed using a surgical procedure known as a myomectomy. However, the operation is not suitable for every type of fibroid. Your gynaecologist (specialist in the female reproductive system) will be able to tell you whether a myomectomy is possible and what the complications are.

When they are possible, myomectomies are very effective operations. However, in a quarter to a third of all people who have a myomectomy, the fibroids grow back again.

If your heavy periods are caused by something other than fibroids, there are several surgical procedures that can be carried out. Your specialist will be able to discuss them with you, including the benefits and any associated risks.

Common surgical procedures for treating heavy periods that are not caused by fibroids include:

  • endometrial ablation: where the womb lining is destroyed
  • hysterectomy: surgical removal of the womb, which may sometimes also involve the removal of the cervix (neck of the womb), fallopian tubes and ovaries (oophorectomy)

Endometrial ablation

There are different techniques that can be used for endometrial ablation. These include:

  • microwave endometrial ablation: in which a probe that uses microwave energy (a type of radiation) is inserted into the womb to heat up and destroy the womb lining  
  • thermal balloon ablation: in which a balloon is inserted into your womb and is inflated and heated to destroy the womb lining

These procedures can be carried out under local anaesthetic (painkilling medication) or general anaesthetic (where you are unconscious). They are fairly quick to perform, taking around 20 minutes, and you can often go home the same day.

You may experience some vaginal bleeding for a few days after endometrial ablation which is similar to a light period. Use sanitary towels rather than tampons. Some women can have bloody discharge for three or four weeks.

You may also experience tummy cramps, similar to period pains, for a day or two. These can be treated with painkillers, such as paracetamol.


A hysterectomy (removal of the womb) will stop any future periods, but it should only be considered after other options have been tried or discussed. The hysterectomy operation and recovery time are longer than for other surgical techniques for treating heavy periods.

A hysterectomy is only used to treat menorrhagia following a thorough discussion with your specialist to outline the benefits and disadvantages of the procedure. See the Health A-Z topic about Hysterectomies for more information.

Passing frequent, watery stools when you go to the toilet.
Fallopian tubes
The tubes connecting the ovaries to the womb.
Hormones are groups of powerful chemicals that are produced by the body and have a wide range of effects.
Indigestion is pain or discomfort in the upper abdomen (tummy).
Inflammation is the body's response to infection, irritation or injury, which causes redness, swelling, pain and sometimes a feeling of heat in the affected area.
The pair of reproductive organs that produce eggs and sex hormones in females.
The womb (or uterus) is a hollow, pear-shaped organ in a woman where a baby grows during pregnancy.

Content provided by NHS Choices www.nhs.uk and adapted for Ireland by the Health A-Z.

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