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Heavy periods


Heavy periods are common. In most cases no cause can be found. In some cases a cause is found, including endometriosis, fibroids and other conditions. There are a number of ways of improving heavy periods and making them more manageable. Options include medication to reduce bleeding, a type of intrauterine system - sometimes called a coil - placed in the womb (uterus) or an operation.

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What is considered a heavy period?

Many women describe their periods as heavy. However, it is often difficult to know whether periods are normal or heavy compared with those of other women. Some women who feel they have heavy periods actually have an average blood loss. Some women who feel they have normal periods actually have a heavy blood loss. Most of the blood loss usually occurs in the first three days with either normal or heavy periods.

When is a heavy period too heavy?

It is difficult to measure blood loss accurately. Some medical definitions of blood loss during a period are:

  • A normal period is a blood loss between 30 and 40 ml (six to eight teaspoonfuls) per month. Bleeding can last up to eight days but bleeding for five days is average.

  • A heavy period is a blood loss of 80 ml or more. This is about half a teacupful or more. However, it is difficult to measure the amount of blood lost during a period.

  • For practical purposes, a period is probably heavy if it causes one or more of the following:

    • Bleeding through to clothes or bedding.

    • Needing frequent changes of sanitary towels or tampons, such as changing a pad or tampon every hour.

    • Needing double sanitary protection (tampons and towels).

    • Soaking of bedclothes.

    • Passing large blood clots.

    • Restrictions to normal lifestyle because of heavy bleeding.

  • Menorrhagia means heavy periods that recur each month where the blood loss interferes with your quality of life, for example, if it affects normal activities such as going out, working or shopping. Menorrhagia can occur alone or in combination with other symptoms.

What causes heavy periods?

Often there is no specific cause for heavy periods but in other cases a cause can be found.

Unknown cause

When the cause is unknown this is called dysfunctional uterine bleeding or idiopathic menorrhagia. This is the case about half the time. In this condition, the womb (uterus) and the ovaries are normal. It is not a hormonal problem. Ovulation is often normal and the periods are usually regular.

Heavy periods due to dysfunctional uterine bleeding are more common in the first few years after starting periods and also in the months running up to the menopause. At these times the periods are often irregular as well as heavy. There is a good chance that heavy periods in teenagers will settle down over a few years and become less heavy. However, very painful periods can suggest endometriosis and should be investigated if persistent.

Other causes

These are less common. They include the following:

  • Fibroids. These are non-cancerous (benign) growths in the muscle of the womb. They sometimes cause no problems but often cause symptoms such as heavy periods.

  • Other conditions of the womb - for example:

  • Hormonal problems. Periods can be irregular and sometimes heavy when not ovulating every month. This can occur in some women with polycystic ovary syndrome. Women with an underactive thyroid gland may have heavy periods.

  • The intrauterine contraceptive device (IUCD, or coil). Sometimes an IUCD causes heavy periods. However, a special hormone-releasing IUCD called the intrauterine system (IUS) can actually treat heavy periods (see 'Levonorgestrel intrauterine system (LNG-IUS)' in the treatment section below).

  • Pelvic infections. There are different infections that can sometimes lead to heavy bleeding developing. For example, chlamydia can occasionally cause heavy bleeding. These infections can be treated with antibiotics. See the separate leaflet called Pelvic Inflammatory Disease.

  • Warfarin or similar medicines interfere with blood clotting. When taking one of these medicines for other conditions, heavier periods may be a side-effect.

  • Some medicines used for chemotherapy can also cause heavy periods.

  • Blood clotting disorders, such as von Willebrand disease, are rare causes of heavy bleeding. Other symptoms are also likely to develop, such as easy bruising or bleeding from other parts of the body.

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When to see a doctor about heavy period bleeding

It is advisable to discuss with a doctor if periods have changed and become heavier than previously. This would usually be after three or four periods in a row have changed. It is normal for periods to occasionally feel different but then return to normal. For most women, the cause is unclear and there is no abnormality of the womb (uterus) or hormones even with a persistent change in periods.

What can doctors do for a heavy period?

A doctor may want to do an internal (vaginal) examination to examine the neck of the womb (cervix) and also to assess the size and shape of the womb. However, an examination is not always necessary, especially in younger women who do not have any symptoms to suggest anything other than dysfunctional uterine bleeding.

A blood test to check for anaemia may be performed. Women who bleed heavily each month may not take in enough iron in their diet to replace the blood that they lose. (Iron is needed to make blood cells.) This can lead to iron deficiency anaemia which can cause tiredness and other symptoms. Up to 2 in 3 women with recurring heavy periods develop anaemia.

If the vaginal examination is normal (as it is in most cases) and there are no other associated symptoms, no further tests may be needed. The diagnosis is usually dysfunctional uterine bleeding and treatment may be started if required. Further tests may be advised for some women, especially if there is concern that there may be a cause for the heavy periods other than dysfunctional uterine bleeding. Examples include:

  • Bleeding between periods or irregular bleeding.

  • Bleeding or pain during, or just after, sex.

  • Having pelvic pain apart from normal period pains.

  • Having severe period pains.

  • Having a vaginal discharge.

  • Having a persistent change in the usual pattern of bleeding.

  • Having symptoms suggesting a hormonal problem or blood disorder.

If tests are advised then they may include one or more of the following:

  • An ultrasound scan of the womb. This is a painless test which uses sound waves to create images of structures inside your body. The probe of the scanner may be placed on the tummy (abdomen) to scan the womb. A small probe is also often placed inside the vagina to scan the womb from this angle. An ultrasound scan can usually detect any fibroids, polyps, or other changes in the structure of the womb.

  • Internal swabs. This may be done if an infection is the suspected cause of the heavy bleeding. A swab is a small ball of cotton wool on the end of a thin stick. It can be gently rubbed in various places to obtain a sample of mucus, discharge, or some cells. This is usually done by the woman herself nowadays although may be done by a clinician during an examination. A swab is usually taken from the top of the vagina and also from the cervix. The samples are then sent away to the laboratory for testing.

  • Endometrial sampling. This is a procedure in which a thin tube is passed into the womb. Gentle suction is used to obtain small samples (biopsies) of the lining of the uterus (endometrium). This is usually done without an anaesthetic. The samples are looked at under the microscope for abnormalities.

  • A hysteroscopy. This is a procedure in which a doctor can look inside the womb. A thin telescope is passed into your womb through the cervix via the vagina. This too can often be done without an anaesthetic. Small samples can also be taken during this test.

  • Blood tests. These may be taken if, for example, an underactive thyroid gland or a bleeding disorder is suspected.

Keeping a menstrual diary

It may be worth keeping a diary for a few periods (before and after any treatment). The number of sanitary towels or tampons needed each day are recorded, as well as the number of days of bleeding.

A diary is useful for both patient and doctor to see:

  • How bad symptoms are and whether treatment is needed.

  • If treatment is started, whether it is helping. Some treatments take a few menstrual cycles to work fully. A diary it helps can help to assess exactly how things are going.

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Heavy period treatment

Treatment will depend on the cause - as mentioned above, often no cause is found. However, there are still treatments that can make periods lighter. The benefits and the possible side-effects will be discussed before deciding which to use.

Treatment aims to reduce the amount of blood loss. The rest of this leaflet discusses treatment options for women who have regular but heavy periods with no clear cause. This can normally be easily treated by a clinician within a GP practice; occasionally a referral to a gynaecologist might be made if the bleeding is not responding to normal treatments.

If there is an underlying cause, such as a fibroid or endometriosis, treatment options may be different. See the relevant leaflets to read about treatment for these conditions.

Not treating

This is an option if the heavy periods are not interfering too much with normal life. Women may be reassured that there is no serious cause for the heavy periods and may be able to live with them. A blood test may be advised every so often to check for anaemia. Iron tablets can correct anaemia.

Levonorgestrel intrauterine system (LNG-IUS)

The LNG-IUS treatment usually works very well. The LNG-IUS is similar to an IUCD, or coil. It is inserted into the womb (uterus) and slowly releases a small amount of a progestogen hormone called levonorgestrel. The amount of hormone released each day is tiny but sufficient to work inside the womb. In most women, bleeding becomes either very light or stops altogether within 3-6 months of starting this treatment. Period pain is usually reduced too. The LNG-IUS works mainly by making the lining of the womb very thin.

The LNG-IUS is a long-acting treatment. Most devices last for five years, although the device can be taken out at any time. One version, called Jaydess®, only lasts for three years. It can be used for contraception but not just to treat heavy periods. However, it is slightly smaller and easier to fit than other types of LNG-IUS, so is sometimes considered in women who have not yet had children.

LNG-IUS is particularly useful for women who require long-term contraception, as it is also a reliable form of contraception. See the separate leaflet called Intrauterine System (IUS) for more details.

Tranexamic acid tablets

Tranexamic acid tablets are an option if the LNG-IUS is not suitable or not wanted. Treatment with tranexamic acid can reduce the heaviness of bleeding by almost half in most cases. However, the number of days of bleeding during a period is not reduced and neither is period pain.

A tablet is taken 3-4 times a day, for 3-5 days during each period. Tranexamic acid works by reducing the breakdown of blood clots in the womb. In effect, it strengthens the blood clots in the lining of the womb, which leads to less bleeding. If side-effects occur they are usually minor but may include an upset stomach.

Anti-inflammatory painkillers

There are various types and brands. Some are available only on prescription but ibuprofen and naproxen are both available over the counter from pharmacies; mefenamic acid can only be prescribed. These medicines reduce the blood loss by about a quarter in most cases.

They also ease period pain. You need to take the tablets for a few days during each period. They work by reducing the high level of prostaglandin in the lining of the womb. This is a chemical which seems to contribute to heavy periods and period pain. However, they do not reduce the number of days the period lasts.

Side-effects occur in some people and may include an upset stomach. Women with a history of a duodenal or stomach ulcer should only take these medicines on a doctor's advice. See the separate leaflet called Anti-inflammatory Painkillers for more details.

Many women take both anti-inflammatory painkillers and tranexamic acid tablets for a few days over each period, as they work in different ways. This combination of tablets can be very effective for many women with heavy periods.

The combined oral contraceptive (COC) pill

This reduces bleeding by at least a third in most women. It often helps with period pain too. It is a popular treatment with women who also want contraception but who do not want to use the LNG-IUS. If required, this can be taken in addition to anti-inflammatory painkillers (described above), particularly if period pain is a problem.

See the separate leaflet called The Combined Oral Contraceptive (COC) Pill for more details. Other options which work in a similar way are combined hormonal contraceptive rings or patches.

Progestogen contraceptives

The contraceptive injection and the contraceptive implant also tend to reduce heavy periods. For example, up to half of women on the contraceptive injection have no periods after a year. The progestogen-only pill will reduce bleeding for most women (and many women get no bleeding at all on the POP) so is another potential option.

They are not usually given as a treatment just for heavy periods. However, they may be a good option in women who also want to consider contraception. See the separate leaflets called Contraceptive Injection and Contraceptive Implant for more details.

Other hormones

Norethisterone is a hormone (progestogen) medicine. It is not commonly used to treat heavy periods but it is sometimes considered if other treatments have not worked, are unsuitable or are not wanted. Norethisterone is given to take on days 5-26 of your menstrual cycle (day 1 is the first day of your period). Taking norethisterone in this way does not act as a contraceptive.

The reason that norethisterone is not commonly used as a regular treatment is because it is less effective than the other options. Also many women develop side-effects and there are risks of blood clots (in the lungs and legs) which can have serious complications. However, norethisterone may be used as a temporary measure to stop very heavy menstrual bleeding (see 'Emergency treatment to rapidly stop heavy bleeding', below).

It is more common nowadays to use medroxyprogesterone in this way. Although it is an unlicensed indication for this medicine, the risks of blood clots are less and therefore it is thought to be safer.

Other medicines

Other hormonal treatments, such as gonadotrophin-releasing hormone (GnRH) analogues, are occasionally used by specialists in hospital. However, they are not routine treatments, due to various side-effects that commonly occur, including liver complications when using ulipristal for fibroids, for example.

Having surgery is not a first-line treatment but it can be an option if the above treatments do not help or are unsuitable.

Removing or destroying the lining of the womb is one surgical option. This is called endometrial ablation. This can be done in a number of ways, using heat, laser or energy waves. It can be done by passing an instrument into the womb through the vagina, or can be done through the abdomen, using ultrasound or magnetic resonance imaging (MRI) scans to guide the energy waves to the right place.

The aim is to remove as much of the lining of the womb as possible. Usually this is very successful but sometimes it needs to be repeated as it is not permanent.

Hysterectomy is the traditional operation where the womb is totally removed. However, hysterectomy is done much less commonly these days since endometrial ablation became available in the 1990s. It is a more major operation, with more possible problems and a longer recovery time. It may be considered if all other treatment options have not worked. See the separate leaflet called Hysterectomy.

Emergency treatment to rapidly stop heavy bleeding

Some women have very heavy bleeding during a period. This can cause a lot of blood loss, and distress. One option as an emergency treatment is to take a course of norethisterone or medroxyprogesterone tablets. These are both progestogen medicines. Progestogens act like the body's natural progesterone hormones - they control the build-up of cells lining the womb (uterus).

So, if a period is very heavy or prolonged, norethisterone or medroxyprogesterone tablets might be advised. They are usually taken 2-3 times a day for up to 10 days. Bleeding usually stops within 24-48 hours of starting treatment. As stated above, medroxyprogesterone is unlicensed for this indication but commonly used due to the lower risks associated with it.

Further reading and references

Article history

The information on this page is written and peer reviewed by qualified clinicians.

  • Next review due: 11 Jul 2028
  • 13 Jul 2023 | Latest version

    Last updated by

    Dr Pippa Vincent, MRCGP

    Peer reviewed by

    Dr Colin Tidy, MRCGP
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