Menorrhagia (heavy periods)

About heavy periods

The amount of blood lost during a period varies from one woman to another. On average, during your period, you will probably lose between 35 and 40ml of blood (two to three tablespoons). If you regularly lose more than this, or if your periods affect you physically and emotionally, you may have menorrhagia. 

Symptoms of heavy periods

The following signs can indicate that you have heavy periods. For example, you may:

  • need to change your sanitary towel every two hours (or more frequently)
  • need to use double sanitary protection (tampons and towels)
  • pass large blood clots
  • bleed through to your clothes or bedding (sometimes called ‘flooding’)

If your periods affect your normal activities such as going out, working or shopping, this may also mean that you have menorrhagia.

These signs may be caused by problems other than menorrhagia. If you have any of these signs, see your GP for advice.

Causes of heavy periods

The exact reasons why you may develop menorrhagia aren’t fully understood at present. However, there are certain conditions that can make heavy periods more likely, such as:

  • fibroids or polyps (growths of tissue) in your womb
  • endometriosis (a condition in which cells that normally line the womb grow outside the womb in other parts of the body)
  • pelvic inflammatory disease - an infection of the female reproductive organs, usually caused by a sexually transmitted infection (STI)
  • polycystic ovary syndrome (a condition in which the ovaries aren't working properly)
  • bleeding disorders
  • an underactive thyroid
  • medications such as anticoagulants

It’s also possible that certain types of intrauterine contraceptive devices (IUD or coil) can cause you to have heavy periods. Speak to your GP for more information.

Complications of heavy periods

Menorrhagia can cause iron deficiency and anaemia. Anaemia is a condition where you have too few red blood cells or not enough haemoglobin in your blood. Around two in three women with heavy periods have iron-deficiency anaemia.

Menorrhagia can make you feel self-conscious and embarrassed during your period. It may also cause you to have mood swings or affect your sex life.

Diagnosis of heavy periods

Your GP will ask about your symptoms and examine you. He or she may also ask you about your medical history.

You may have the following tests to confirm diagnosis.

  • Blood tests to check the levels of haemoglobin and thyroid hormones.
  • Abdominal ultrasound or a transvaginal ultrasound, which are simple ways of checking your womb for any problems.

Your GP may refer you to a gynaecologist (a doctor who specialises in women’s reproductive health) for further tests.

Treatment of heavy periods

Treatment of menorrhagia depends on its underlying cause. If a cause can’t be found, your GP will recommend treatments to reduce the heavy bleeding and prevent iron-deficiency anaemia.


Your GP may recommend you try medicines such as:

  • the combined contraceptive pill
  • tranexamic acid
  • non-steroidal anti-inflammatory drugs (NSAIDs)
  • oral or injected progestogen

Always ask your GP or pharmacist for advice and read the patient information leaflet that comes with your medicine.

Intrauterine system (IUS)

If you’re not trying to get pregnant, your GP may recommend you have an IUS fitted (eg Mirena). The IUS contains the hormone levonorgestrel, which is slowly released and stops the lining of your womb from growing. Your GP will only recommend this if you're happy to have it fitted for at least a year. The IUS lasts up to five years and should help to improve your menorrhagia within the first three to six months. During this time you may have irregular bleeding, but this is normal. But if your symptoms don’t improve in this time, speak to your GP.

Non-surgical treatments

Uterine artery embolisation

This may be recommended if your heavy periods are caused by fibroids. A chemical is injected into the blood vessels that take blood to your fibroids (uterine arteries). The chemical blocks the blood vessels causing the fibroids to shrink.

Surgical treatment


This is an operation to remove your fibroids. It may be recommended if a uterine artery embolisation hasn’t worked.

Endometrial ablation

This is a surgical treatment where most of your womb lining is destroyed or removed using energy such as microwaves or heat. It's not usually recommended if you have fibroids or if you want to have children in the future.


This is an operation to remove your womb. It’s usually only done if other treatments haven’t worked. After a hysterectomy, you will no longer have periods and won’t be able to become pregnant.

Is it more difficult to get pregnant if you have heavy periods?


No, heavy periods (also known as menorrhagia) alone won’t make it more difficult for you to get pregnant, although some causes of menorrhagia may affect your fertility.


Heavy periods alone won’t affect your ability to get pregnant. However, certain causes of menorrhagia can make it more difficult. For example, growths in the womb such as polyps or fibroids can make it more difficult for the fertilised egg to attach to the lining of the womb. Pelvic inflammatory disease can also cause infertility.

Tell your GP if you're trying to get pregnant as this will affect the treatment you are recommended for heavy periods.

Are there any side-effects from the medicines for heavy periods?


Yes, medicines for heavy periods can cause some side-effects.


Side-effects are the unwanted effects of taking a medicine. If you have side-effects, it's important to talk to your GP or the healthcare professional who prescribed your medicine before you stop taking it.

For example, if you have an intrauterine system (IUS) (eg Mirena) fitted, you may notice that the pattern of your periods changes. You may also have other, uncommon side-effects, such as:

  • feeling sick
  • headaches
  • tender breasts
  • painful or irregular periods, or no periods at all
  • abdominal (tummy) or pelvic pain
  • acne
  • weight gain
  • bloating
  • increased hair growth or hair loss
  • mood changes, including depression or nervousness

If you’re taking tranexamic acid, you may feel sick, vomit or have diarrhoea. You may also have problems with your vision, but this is rare.

If you’re taking non-steroidal anti-inflammatory drugs (NSAIDs), you may feel sick, vomit, have indigestion, heartburn or diarrhoea. It’s also possible to develop a stomach ulcer, but this is rare.

If you’re taking the combined oral contraceptive pill, you may have bloating, breast tenderness, headaches, acne and mood changes.

Speak to your GP for more information about the side-effects of any medicines you’re taking for menorrhagia.

When is surgery for heavy periods recommended?


This will depend on your own individual circumstances, including what is causing your menorrhagia.


Your treatment will vary depending on whether a cause can be found for your heavy periods, and if so, what this is. Your GP will usually first recommend medicines and non-surgical treatments to reduce the heavy bleeding and prevent iron-deficiency anaemia from developing.

Surgery is usually only recommended if other treatments for menorrhagia haven’t worked.