Heavy periods (menorrhagia)


Heavy periods (menorrhagia)


Heavy periods (menorrhagia)


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

See your GP if you are worried about heavy bleeding during or between your periods.

How much is heavy bleeding?

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

The average amount of blood lost during a period is 30-40 millilitres (ml), with 9 out of 10 women losing less than 80ml. Heavy menstrual bleeding is considered to be 60-80ml or more in each cycle.

However, it is rarely necessary to measure blood loss. 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.

A good indication that your blood loss is excessive is if:

you feel 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

What causes heavy periods?

In most cases, no underlying cause of heavy periods is identified. However, some conditions and treatments have been linked to menorrhagia, including:

uterine fibroids

intrauterine contraceptive devices (IUDs)

anticoagulant medication

polycystic ovary syndrome (PCOS)


Diagnosing heavy periods

Your GP should be able to diagnose heavy periods from your symptoms alone.

The cause of the problem may sometimes need to be investigated further. This will usually involve having a pelvic examination. A blood test may also sometimes be recommended to check for anaemia (iron deficiency).

If a cause is still not found, then you may have an ultrasound scan.


Treating heavy periods 

In some cases, heavy periods do not need to be treated, as they can be a natural variation and may not disrupt your lifestyle.

If treatment is necessary, medication is most commonly used first. However, it may take a while to find the medication most suitable for you, as their effectiveness is different for everyone and some also act as contraceptives.

If medication doesn't work, surgery may also be an option.


Causes of heavy periods

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

Otherwise, possible causes of heavy periods include the following:

cervical or endometrial polyps – non-cancerous growths in the lining of the womb or cervix (neck 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)

uterine fibroids – 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) – 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

adenomyosis – when glands from the lining of the uterus become embedded in the uterus muscle

an underactive thyroid gland (hypothyroidism) – this may cause fatigue, constipation, intolerance to cold, and hair and skin changes

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 that reduces the blood's ability to clot

chemotherapy – cancer treatment

Diagnosing heavy periods

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

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

GP consultation

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

your medical history

the nature of your bleeding

any related symptoms that you have

They will also ask 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 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 want to know if you have any bleeding between periods (intermenstrual bleeding) or after sexual intercourse (postcoital bleeding), and whether you experience any pelvic pain.

To help determine the cause of your menorrhagia, you may have a physical examination, particularly if you have pelvic pain or bleeding between periods or after sex.

Your GP is likely to want to know the contraception 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 will also be noted.

They will also ask 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 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 intermenstrual or postcoital bleeding or have pelvic pain, you will need further tests to rule out serious illness, such as an underlying cancer (which is very rare).

Pelvic examination

If you need to have a pelvic examination, your GP will ask if you would like a female assistant to be present. 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 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 you are unsure about. A pelvic examination should not be carried out without your 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 test is usually carried out for all women who have heavy periods. This can detect iron deficiency anaemia, 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 most suitable for you and how long you need to take it for.

Ultrasound scan

If you have heavy menstrual bleeding and the cause is still unknown after you've had tests, an ultrasound scan of your womb may be carried out 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 transvaginal scan is often used, which involves a small probe being inserted into the vagina to take a close-up image of your womb.

Treating heavy periods

Medication is the main treatment for heavy periods (menorrhagia), but surgery may be used in some cases.

If menorrhagia is diagnosed, your GP will discuss possible treatment options with you, including:

the effectiveness of treatments

the likelihood of any adverse effects after treatment

whether contraception will be required

the implications for your fertility

In some cases, treatment is not necessary. If the heavy bleeding doesn't affect your life or no serious cause is suspected, you may just be reassured that bleeding can vary over time for some women.

The aim of treating menorrhagia is to:

reduce or stop excessive menstrual bleeding

improve the quality of life of women with menorrhagia

prevent or correct iron deficiency anaemia caused by heavy menstrual bleeding

Read on to learn about the different treatments you may be offered. You can also see a summary of the pros and cons of these treatments, which allows you to easily compare your options.


Medication is recommended as the first line of treatment 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 a medication is not effective, 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 and your GP decide which is the most suitable treatment.

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

Levonorgestrel-releasing intrauterine system (LNG-IUS)

The levonorgestrel-releasing intrauterine system (LNG-IUS) is a small plastic device that is inserted into your womb and slowly releases a hormone called progestogen.

It prevents the lining of your womb growing quickly and is also a form of contraceptive. LNG-IUS does not 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


no periods at all (amenorrhoea)

LNG-IUS 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.

Tranexamic acid

If LNG-IUS is unsuitable (for example, if contraception is not desired), tranexamic acid 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 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 four 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).

Possible side effects include indigestion and diarrhoea.

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 until heavy bleeding has stopped.

The NSAIDs that are recommended for treating menorrhagia are:

mefenamic acid



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. Common side effects 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 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 contraceptive pills, often referred to as the pill, can be used to treat menorrhagia. They contain 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 menorrhagia is they offer a more readily reversible form of contraception than LNG-IUS. They also have the benefit of regulating your menstrual cycle and reducing painful periods (dysmenorrhoea).

The combined oral contraceptive works by preventing your ovaries 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

nausea (feeling sick)

fluid retention

breast tenderness

 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 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 is not an effective form of contraception and can have unpleasant side effects, including:

weight gain  

breast tenderness

short-term acne

Oral progestogens such as norethisterone are not as effective as tranexamic acid and may not always be able to control heavy bleeding.

 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 growing quickly and 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.

Common side effects of injected progestogen include:

weight gain

irregular bleeding

absence of periods (amenorrhoea)

a delay in your ability to become pregnant for 6 to 12 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 12 weeks for as long as treatment is required.

 Gonadotropin releasing hormone analogue 

Gonadotropin releasing hormone analogue (GnRH-a) is a type of 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. However, it can be expensive and may cause hormone abnormalities (hypogonadism) similar to the menopause, with effects including hot flushes, increased sweating and vaginal dryness. This means GnRH-a is not a routine treatment, but may be used while you await surgery.


Your specialist may suggest surgery if medication is 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


 Uterine artery embolisation (UAE) 

Uterine artery embolisation (UAE) is a minimally invasive procedure carried out through a small tube inserted 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 subsequent six months.

Advantages of UAE include:

it is usually successful in women whose heavy periods are caused by fibroids

serious complications are rare

you only need to spend one night in hospital

However, 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 known as a myomectomy. However, this 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 appropriate, myomectomies are effective. However, in some cases the fibroids grow back.


If your heavy periods are not caused by fibroids, several surgical procedures can be carried out, including:

endometrial ablation – where the womb lining is destroyed

hysterectomy – surgical removal of the womb, which sometimes also involves removal of the cervix (neck of the womb), fallopian tubes and ovaries (oophorectomy)

Your specialist can discuss these with you, including the benefits and any associated risks.

 Endometrial ablation 

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

microwave endometrial ablation - 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 - a balloon is inserted into your womb and inflated and heated to destroy the womb lining

These procedures can be carried out either under local anaestheticor general anaesthetic. 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 after the procedure. These can be treated with painkillers, such as paracetamol or ibuprofen.

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 is usually recommended that you don't get pregnant after you have had endometrial ablation, as the risk of problems such as miscarriageis high.

The failure rate for endometrial ablation is about 25-35%. If it fails, you may be offered a repeat treatment.

More information about endometrial ablation is available from the Royal College of Obstetricians and Gynaecologists (RCOG), who have produced a leaflet called Information for you after an endometrial ablation (PDF, 3.75Mb).



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 menorrhagia after a thorough discussion with your specialist to outline the benefits and disadvantages of the procedure.


You will no longer be able to get pregnant after a hysterectomy.