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, approaching menopause.  It is defined as blood loss greater than 80ml (equal to 1/3 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 impacting on your quality of life, causing you to be housebound, interrupting your daily activities or causing you stress and anxiety.  The following signs may indicate you are experiencing heavy bleeding:

  • Bleeding or 'flooding' not contained within a pad/tampon (especially 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 7-8 days

How can heavy bleeding affect you?

You may:

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

What causes heavy bleeding?

About 50% of women with heavy menstrual bleeding have no abnormalities in their uterus. It may 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 may be related to:

Pregnancy or complications of pregnancy Please contact your doctor if you have bleeding during pregnancy.
Polycystic Ovarian Syndrome (PCOS) Some women may have heavy menstrual bleeding if the lining of the uterus is thickened- can lead to pre cancerous or cancerous changes.
Endometriosis Occurs when the tissue that lines 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 where excessive bleeding can occur such as Von Willebrand disease (more common in teenagers)
  • chronic kidney or liver disease

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

How is heavy bleeding diagnosed?

After a thorough history and clinical examination (including a pap smear and swabs), your doctor may order blood tests and/or a pelvic ultrasound to eliminate some of the possible causes listed previously. The gold standard is to perform a hysteroscopy and curette in all women over 35 years of age who have heavy menstrual bleeding to rule out endometrial hyperplasia or cancer[2]. This is where the lining of the womb is looked at with a telescope, the hysteroscope, and is then lightly scraped away and a biopsy (a sample of cells) is taken for examination.

How is heavy bleeding treated?

Your doctor may 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%. 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.[3]

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 may 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 may get you to take a blood test and recommend iron therapy if levels are low. This usually involves taking an iron supplement daily.


  1. Cox SM, Cromwell D, Mahmood T, Templeton A et al. 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 et al. Menstrual blood loss – a population study. Variation at different ages and attempts to define normality. Acta Obste Gynaecol Scand 1966; 45:320.

  2. Dijkhuizen FP, MolBW, 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

  3. 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 24 October 2017 — Last reviewed 09 December 2013

** Currently under review **

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 December 2013.

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