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Overview - Heavy periods

Heavy periods are common, but they can affect your everyday life.

They do not always have an underlying cause. But the cause can be problems such as fibroids or endometriosis.

Non-urgent advice: See a GP if:

  • you're worried about your bleeding
  • your periods have become heavier
  • you also have other symptoms, such as period pain or bleeding between your periods

Treatments for heavy periods include:

Heavy bleeding

It's difficult to define a heavy period because menstrual bleeding varies. Heavy for 1 woman may be normal for another.

Most women lose less than 16 teaspoons of blood (80ml) during their period. The average is about 6 to 8 teaspoons.

Heavy menstrual bleeding is losing 80ml or more in each period, having periods that last longer than 7 days, or both.

It's not usually necessary to measure blood loss. You'll have a good idea of how much bleeding is normal for you during your period. You can tell when this changes.

Signs that your periods are heavy is if you:

  • have to change your sanitary products every hour or 2
  • pass blood clots larger than 2.5cm (about the size of a 50c coin)
  • bleed through to your clothes or bedding
  • need to use 2 types of sanitary product together (for example, tampons and pads

Causes of heavy periods

In about half of heavy menstrual bleeding cases, no underlying cause is found.

But there are some conditions and treatments that can cause heavy menstrual bleeding.

Some conditions of the womb and ovaries can cause heavy bleeding, including:

  • fibroids – non-cancerous growths that develop in or around the womb
  • endometriosis – where the tissue that lines the womb (endometrium) grows outside the womb, such as in the ovaries and fallopian tubes
  • adenomyosis – when tissue from the womb lining becomes embedded in the wall of the womb
  • pelvic inflammatory disease (PID) – an infection in the upper genital tract (the womb, fallopian tubes or ovaries) that can cause pain, vaginal bleeding or discharge, and a high temperature
  • endometrial polyps – non-cancerous growths in the lining of the womb or cervix (neck of the womb)
  • cancer of the womb – the most common symptom is abnormal bleeding, especially after the menopause
  • polycystic ovary syndrome (PCOS) – a condition that affects how the ovaries work causing irregular and sometimes heavy periods

Other conditions that can cause heavy periods include:

  • blood clotting disorders, such as Von Willebrand disease
  • hypothyroidism (an underactive thyroid gland) – where the thyroid gland does not produce enough hormones and causes tiredness, weight gain and feelings of depression
  • diabetes

Medical treatments that can sometimes cause heavy periods include:

  • an IUD (intrauterine contraceptive device or 'the coil') – this can make your periods heavier for the first 3 to 6 months after insertion
  • anticoagulant medicine – taken to prevent blood clots
  • some medicines used for chemotherapy
  • some herbal supplements - these can affect your hormones and may affect your periods, such as ginseng, ginkgo and soya

Seeing your GP

Your GP will ask you about your heavy bleeding, any changes to your periods and any other symptoms you have. For example, bleeding between your periods or period pain.

You may need a blood test to check for iron deficiency anaemia.

Your GP may also suggest a physical examination. They may refer you for more tests to try to find any underlying cause for your heavy periods.

Further tests may include:

  • other blood tests
  • an ultrasound scan
  • a hysteroscopy – where your doctor checks the inside of your womb. They pass a narrow telescope with a light and camera at the end into the womb through the vagina

Find out more about diagnosing heavy periods

Read more about period problems

Treating heavy periods

There are many treatment options for heavy periods. These depend on the cause of your heavy periods, your general health and your preferences.

Treatment for heavy periods include:

  • an intrauterine system (IUS) – your doctor inserts a small device that contains the hormone progestogen in your womb. This is often the first treatment offered
  • medicines without hormones – such as tranexamic acid or non-steroidal anti-inflammatory drugs (NSAIDs)
  • medicines with hormones – such as the combined oral contraceptive pill or progestogen tablets
  • endometrial ablation – a procedure to remove the lining of the womb
  • myomectomy – surgery to remove fibroids
  • uterine artery embolisation – a procedure to shrink fibroids
  • hysterectomy – surgery to remove to the womb

Content supplied by the NHS and adapted for Ireland by the HSE

Page last reviewed: 7 July 2021
Next review due: 7 July 2024

This project has received funding from the Government of Ireland’s Sláintecare Integration Fund 2019 under Grant Agreement Number 123.