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Heavy Periods (Menorrhagia)

Heavy Periods (Menorrhagia)

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

About 1 in 3 women describe their periods as heavy. However, it is often difficult to know if your periods are normal or heavy compared with 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.

Female reproductive organs (periods)

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 that you lose during a period. For practical purposes, a period is probably heavy if it causes one or more of the following:
    • Flooding through to clothes or bedding.
    • You need frequent changes of sanitary towels or tampons.
    • You need double sanitary protection (tampons and towels).
    • You pass large blood clots.
  • Menorrhagia means heavy periods that recur each month. Also, that the blood loss interferes with your quality of life. For example, if it stops you doing normal activities such as going out, working or shopping. Menorrhagia can occur alone or in combination with other symptoms.

There is often no specific cause for heavy periods (called dysfunctional uterine bleeding). Some possible causes include fibroids, infection, cancer of the lining of the womb (endometrial cancer), polycystic ovary syndrome or an underactive thyroid gland. Always see a doctor to get it checked out.

Unknown causes

This is called dysfunctional uterine bleeding and is the cause of heavy periods in 4 to 6 out of 10 cases. In this condition, the womb (uterus) and ovaries are normal. It is not a hormonal problem. Ovulation is often normal and the periods are usually regular. It is more common if you have recently started your periods or if you are approaching the menopause. At these times you may find your periods are irregular as well as heavy.

Other causes

These are less common. They include the following:

  • Fibroids. These are non-cancerous (benign) growths in the muscle of the womb. They often cause no problems, but sometimes cause symptoms such as heavy periods. See separate leaflet called Fibroids for more details.
  • Other conditions of the uterus, which may lead to heavy periods. For example:
  • Hormonal problems. Periods can be irregular and sometimes heavy if you do not ovulate every month. For example, this occurs 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 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)' 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.
  • Warfarin or similar medicines interfere with blood clotting. If you take 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 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.

If you stop taking the contraceptive pill it may appear to cause heavy periods. Some women become used to the light monthly bleeds that occur whilst on the pill. Normal periods return if you stop the pill. These may appear heavier but are usually normal.

  • A doctor may want to do an internal (vaginal) examination to examine your neck of the womb (cervix) and also to assess the size and shape of your womb (uterus). 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 is usually performed. If you bleed heavily each month then you may not take in enough iron in your diet, needed to replace the blood that you lose. (Iron is needed to make blood cells.) This can lead to 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 you are under the age of 40, no further tests are usually 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. For example:

  • Women over the age of 45 who develop heavy periods.
  • If treatment for presumed dysfunctional uterine bleeding does not seem to help.
  • Any woman in whom a doctor detects a large or abnormal uterus, or who has other symptoms which may indicate an underlying problem. For example, if you:
    • Bleed between periods, or have irregular bleeding.
    • Have bleeding or pain during, or just after, sex.
    • Have pain apart from normal period pains.
    • Have any change in your usual pattern of bleeding, particularly if you are over the age of 45.
    • Have 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 your uterus. 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 your tummy (abdomen) to scan the uterus. A small probe is also often placed inside the vagina to scan the uterus from this angle. An ultrasound scan can usually detect any fibroids, polyps, or other changes in the structure of your uterus.
  • 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. A swab is usually taken from the top of your vagina and also from your 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 uterus. Gentle suction is used to obtain small samples (biopsies) of the uterine lining (endometrium). This is usually done without an anaesthetic. This is more likely to be done if you are aged over 45 years, have persistent bleeding or have tried treatment without it helping. The samples are looked at under the microscope for abnormalities.
  • A hysteroscopy. This is a procedure in which a doctor can look inside the uterus. A thin telescope is passed into your uterus through your 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 take if, for example, an underactive thyroid gland or a bleeding disorder is suspected.

It may be worth keeping a diary for a few periods (before and after any treatment). Your doctor may give you a chart which you can fill in. Basically, you record the number of sanitary towels or tampons that you need each day and the number of days of bleeding. Also, note if you have any flooding or interruption of normal activities. For an example of a chart, see separate leaflet called Period Blood Loss Chart. 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. If you keep a diary it helps you to remember exactly how things are going.

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 (dysfunctional uterine bleeding). This is the majority of cases. If there is an underlying cause, such as a fibroid or endometriosis, treatment options may be different.

Not treating

This is an option if your periods do not interfere too much with normal life. You may be reassured that there is no serious cause for your heavy periods and you 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)

This 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 uterus. 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 uterus very thin.

The LNG-IUS is a long-acting treatment. Each device lasts for five years, although it can be taken out at any time. It is particularly useful for women who require long-term contraception, as it is also a reliable form of contraception. See separate leaflet called Intrauterine System for more details. This is, however, not usually suitable if you do not need long-term (for at least one year) contraception.

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. You need to take a tablet 3-4 times a day, for 3-5 days during each period. Tranexamic acid works by reducing the breakdown of blood clots in the uterus. In effect, it strengthens the blood clots in the lining of the uterus, 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. Most are available only on prescription but you can buy one called ibuprofen from pharmacies. Your doctor may prescribe ones called mefenamic acid or naproxen. 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 uterus. 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. If you have a history of a duodenal or stomach ulcer, or asthma, you should only take these medicines on a doctor's advice. See 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 really 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, you can take this in addition to anti-inflammatory painkillers (described above), particularly if period pain is a problem. See separate leaflet called Combined Oral Contraceptive Pill for more details.

Long-acting 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. They are not given as a treatment just for heavy periods. However, if you require contraception then one of these may be an option for you. See separate leaflets called Contraceptive Injection and Contraceptive Implant for more details.


Norethisterone is a hormone (progestogen) medicine. It is not commonly used to treat heavy periods. 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 why 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. However, norethisterone may be used as a temporary measure to stop very heavy menstrual bleeding (see 'Emergency treatment to rapidly stop heavy bleeding' below).

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.

Surgical treatment

Having surgery is not a first-line treatment. It is an option if the above treatments do not help or are unsuitable:

  • Removing or destroying the lining of the uterus is an option. This is called endometrial ablation or resection. An instrument is passed into the uterus via the vagina. The aim is to remove as much of the lining of the uterus as possible. This can be done in various ways such as by using heat, microwaves, and freezing treatment (cryotherapy). This treatment prevents women from having children in the future. However, there have been some pregnancies in otherwise fertile women, so it cannot be used as contraception. Usually this is very successful but sometimes it needs to be repeated as it is not permanent. See separate leaflet called Surgical Treatment Options for Heavy Vaginal Bleeding for more information.
  • Hysterectomy is the traditional operation where the uterus 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 for you. See separate leaflet called Hysterectomy for more information.

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 tablets. Norethisterone is a progestogen medicine. 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, your doctor may advise that you take norethisterone tablets. A dose of 5 mg three times daily for 10 days is the usual treatment. Bleeding usually stops within 24-48 hours of starting treatment. If bleeding is exceptionally heavy then 10 mg three times daily may be given. This should then be tapered down to 5 mg three times daily for a week, once your bleeding has stopped.

Heavy periods due to dysfunctional uterine bleeding seem to be more common in the first few years after starting periods. (This is also the case in the months running up to the menopause.) If you are a teenager and have heavy periods, you have a good chance that they will settle down over a few years and become less heavy.

So, for example, if you take treatment for heavy periods whilst a teenager or young adult, it is very likely you will not need it after a few years. On a practical note, there is no reason why a teenager should not use tampons. It can take a bit of practice to learn how to use a tampon but it may make heavy periods easier to manage.

Further reading & references

  • Menorrhagia; NICE CKS, August 2015 (UK access only)
  • Heavy menstrual bleeding; NICE Clinical Guideline (January 2007)
  • Lukes AS, Baker J, Eder S, et al; Daily menstrual blood loss and quality of life in women with heavy menstrual bleeding. Womens Health (Lond Engl). 2012 Sep;8(5):503-11. doi: 10.2217/whe.12.36.
  • Naoulou B, Tsai MC; Efficacy of tranexamic acid in the treatment of idiopathic and non-functional heavy menstrual bleeding: a systematic review. Acta Obstet Gynecol Scand. 2012 May;91(5):529-37. doi: 10.1111/j.1600-0412.2012.01361.x. Epub 2012 Feb 24.
  • Gupta J, Kai J, Middleton L, et al; Levonorgestrel intrauterine system versus medical therapy for menorrhagia. N Engl J Med. 2013 Jan 10;368(2):128-37. doi: 10.1056/NEJMoa1204724.
  • Lethaby A, Hussain M, Rishworth JR, et al; Progesterone or progestogen-releasing intrauterine systems for heavy menstrual bleeding. Cochrane Database Syst Rev. 2015 Apr 30;4:CD002126. doi: 10.1002/14651858.CD002126.pub3.
  • Marjoribanks J, Lethaby A, Farquhar C; Surgery versus medical therapy for heavy menstrual bleeding. Cochrane Database Syst Rev. 2016 Jan 29;1:CD003855. doi: 10.1002/14651858.CD003855.pub3.

Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. Patient Platform Limited has used all reasonable care in compiling the information but makes no warranty as to its accuracy. Consult a doctor or other healthcare professional for diagnosis and treatment of medical conditions. For details see our conditions.

Dr Mary Harding
Peer Reviewer:
Dr Helen Huins
Document ID:
4418 (v42)
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