Heavy bleeding

Heavy bleeding can disrupt your daily life and can be quite distressing. What causes it, how heavy bleeding is diagnosed and what treatments are available are all discussed.

What is heavy bleeding?

1/3 cup, or 80ml

Heavy menstrual bleeding (also known as menorrhagia) is excessive and/or prolonged menstrual bleeding. The amount varies from woman to woman and can change at different stages in your life; for example, in teenage years or approaching menopause. It is defined as blood loss greater than 80ml (equal to one-third of a cup) per cycle, or periods lasting more than seven to eight days. Heavy menstrual bleeding affects about one in five women[1] and is a common problem in the 30-50 year-old age group.

How do you know if your bleeding is too heavy?

It is very difficult to determine whether your bleeding is too heavy. The best guide is to decide whether your period is having an impact on your quality of life – if it is causing you to be housebound, interrupting your daily activities or causing you stress and anxiety. The following signs might indicate you are experiencing heavy bleeding:

  • bleeding or 'flooding' not contained within a pad/tampon (especially when wearing the largest size)
  • changing a pad/tampon every hour or less
  • changing a pad overnight
  • clots greater than a 50-cent piece in size
  • bleeding for more than seven to eight days.

How can heavy bleeding affect you?

You might:

  • feel fatigued, exhausted, dizzy and look pale
  • have low iron levels because of the blood loss
  • have cramping and pain in the lower abdomen
  • need to change sanitary products very frequently
  • fear bleeding through to your clothes, which can affect your daily activities.

What causes heavy bleeding?

About 50% of women with heavy menstrual bleeding have no abnormalities in their uterus. It might be related to hormonal or chemical levels in the endometrium (the internal lining of the uterus) or conditions not yet identified in the endometrium.

In the other 50% of cases, the cause might be related to:

Pregnancy or complications of pregnancy Please contact your doctor if you have bleeding during pregnancy
Polycystic ovary syndrome (PCOS) Some women can have heavy menstrual bleeding if the lining of the uterus is thickened; this can lead to pre-cancerous or cancerous changes
Endometriosis Occurs when tissue similar to that found in the lining of the uterus grows outside of it
Endometrial polyps Usually non-cancerous (benign) growths in the endometrium that look like a large 'teardrop' of tissue
Endometrial hyperplasia An overgrowth of the endometrium, which can progress to cancer
Endometrial cancer Cancer of the uterus
Adenomyosis Endometrium growing in small pockets inside the muscle layer of the uterus
Fibroids Non-cancerous growths or lumps within the uterus wall
Intrauterine device (IUD): A contraceptive device

There is a range of other possible causes that are not as common, such as:

  • hormonal disorders, such as an underactive thyroid gland (hypothyroidism)
  • bleeding disorders in which excessive bleeding can occur, such as Von Willebrand disease (more common in teenagers)
  • chronic kidney or liver disease.

It is important to note that women who have gone through menopause should not have any vaginal bleeding/spotting. If this occurs, see your doctor.

How is heavy bleeding diagnosed?

After a thorough history and clinical examination – including a cervical screening test and swabs – your doctor might order blood tests and/or a pelvic ultrasound to eliminate some of the possible causes listed previously.[2] The gold standard is to perform a hysteroscopy and curette in all women over 35 years of age to rule out endometrial hyperplasia or cancer.[3] This is where the lining of the womb is viewed with a telescope – the hysteroscope – and is then lightly scraped away and a biopsy (a sample of cells) taken for examination.

How is heavy bleeding treated?

Your doctor might prescribe the following treatments to reduce bleeding and pain:

Anti-inflammatory drugs

Can reduce inflammation, pain and blood flow.

Tranexamic acid Can reduce blood loss by about 50%. It is non-hormonal and is taken only on the heavy days of the period.
Insertion of a Mirena® intrauterine device (IUD)

Releases a hormone that thins the endometrium and can reduce bleeding by up to 95% after 12 months.[4]

The oral contraceptive pill Can reduce blood flow by up to 50%
Progestins (synthetic forms of progesterone) Can reduce blood loss by about 30%

Your doctor might recommend endometrial ablation (removal of the endometrium) or a hysterectomy if:

  • medications fail to reduce bleeding
  • there are other symptoms such as pain
  • you discuss the options with your doctor and you both feel it is the most appropriate treatment.

Sometimes with heavy menstrual bleeding, iron levels can get low. Your doctor might get you to take a blood test and recommend iron therapy if levels are found to be low. This usually involves taking an iron supplement daily or, if levels are very low, an iron infusion.


  1. Cox SM, Cromwell D, Mahmood T, Templeton A, La Corte B, van der Meulen J. The delivery of heavy menstrual bleeding services in England and Wales after publication of national guidelines: a survey of hospitals. BMC Health Serv Res. 2013 Nov 25;13(1):491.
    Hallberg L, Högdahl AM, Nilsson L, Rybo G. Menstrual blood loss – a population study. Variation at different ages and attempts to define normality. Acta Obste Gynaecol Scand. 1966;45(3):320–51.

  2. Herman MC, Mol BW, Bongers MY. Diagnosis of heavy menstrual bleeding. Women's Health. 2016;12(1):15–20.

  3. Dijkhuizen FP, Mol BW, Brolmann HA, Heintz AP. The accuracy of endometrial sampling in the diagnosis of patients with endometrial carcinoma and hyperplasia: a meta-analysis. Cancer. 2000;89:1765.

  4. Stewart A, Cummins C, Gold L, Jordan R, Phillips W. The effectiveness of the levonorgestrel-releasing intrauterine system in menorrhagia: a systematic review. BJOG. 2001;108(1):74.

Last updated 23 October 2018 — Last reviewed 10 July 2018

This web page is designed to be informative and educational. It is not intended to provide specific medical advice or replace advice from your health practitioner. The information above is based on current medical knowledge, evidence and practice as at July 2018.

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