Heavy periods (aka menorrhagia) are common. Most of the time no cause can be found but in some cases a cause is found such as endometriosis or fibroids.

In most cases treatment is either with medications or surgery.

What is menorrhagia

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 (about 90%) usually occurs in the first three days with either normal or heavy periods.

A period is considered to be 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 and interferes with your quality of life (if it stops you doing normal activities such as going out, working or shopping).

What causes recurring heavy periods?          

The cause is not known in most cases

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 an 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.

A chemical called prostaglandin may play a part. The amount of prostaglandin in the blood may be different in women with heavy periods. The lining of your uterus is more sensitive to the effects of prostaglandin, which results in heavier periods. In some women, the blood vessels that supply blood to the lining of the womb are larger (dilated), which then results in the blood loss being heavier. This dilatation is also thought to be due to prostaglandins in the body.

Other causes

These are less common. They include the following:

  • Fibroids. These are benign (non-cancerous) growths in the muscle of the uterus. They often cause no problems, but sometimes cause symptoms such as heavy periods.
  • Other conditions of the uterus, such as endometriosis, infections or polyps, may lead to heavy periods. Cancer of the lining of the uterus is a very rare cause. Most cases of endometrial cancer develop in women aged in their 50s or 60s.
  • Hormonal problems. Periods can be irregular and sometimes heavy if you do not ovulate every month like in women with polycystic ovary syndrome. Also 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
  • 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 easily be treated with antibiotics.
  • Warfarin or similar medicines that interfere with blood clotting can lead to heavy periods.
  • Some drugs 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.

Do I need any tests if I have heavy periods?

  • 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 anemia is usually performed. Heavy periods 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, if the are

  • Over the age of 45 who develop heavy periods.
  • If treatment for presumed dysfunctional uterine bleeding does not seem to help.
  • Any woman where a doctor detects a large or abnormal uterus,
  • Who has other symptoms which may indicate an underlying problem like
    • 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 – this can 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 usually taken from the top of your vagina and also from your cervix, and are sent away to the laboratory for testing.
  • Endometrial sampling. This is a test where a thin tube is passed into the uterus and gentle suction is used to obtain small samples (biopsies) of the uterine lining. 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.
  • Hysteroscopy. This is where 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. For example, if an underactive thyroid gland or a bleeding disorder is suspected.

What are the treatment options for heavy periods?

Treatment aims to reduce the amount of blood loss. Treatment options are different if an underlying cause for heavy periods is found like fibroids or endometriosis.

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.

Levonorgestrel intrauterine system (LNG-IUS)

This treatment usually works very well. The LNG-IUS is similar to an intrauterine contraceptive device (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. 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 (40-50%) 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

Your doctor may prescribe ones called Mefenamic acid or Naproxen. These medicines reduce the blood loss by about a third (20-50%) 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 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.

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

The combined oral contraceptive pill (COCP)

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 particularly if period pain is a problem.

 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.


Norethisterone is a 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). However, 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 many women get side-effects, such as bloating, fluid retention, breast tenderness, nausea, headache and dizziness. However, norethisterone is used as a temporary measure to stop very heavy menstrual bleeding.

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 or microwaves. 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.
  • 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 may be considered if all other treatment options have not worked for you.