Heavy menses, also known as menorrhagia, is a very common problem throughout the world. In Singapore, many women delay getting it checked and end up having to be hospitalised to receive a blood transfusion.

The amount of bleeding during menstruation varies greatly from woman to woman and it is very difficult for the patient and the doctor to quantify exactly how much blood is lost. As a result, some women who perceive themselves to have heavy periods in fact have normal blood loss and vice versa.

The normal menstrual cycle should last between 21-35 days and averages 28 days (counting from the first day of menses to the first day of the next menses). Bleeding should be for no longer than 7 days. Any bleeding that occurs between the main menses is known as inter-menstrual bleeding and should be investigated by your doctor.

At menopause, there should be no vaginal bleeding at all once 12 months has elapsed after the last period. If ANY bleeding occurs after this then it should also be investigated by your doctor. Brown or pinkish loss is also regarded as bleeding.

Symptoms of menorrhagia

A woman should consider whether she has heavy menses if she experiences any of the following:

  • Heavy flow soaking through pads or tampons on a regular basis
  • Heavy flow flooding through to the clothing
  • Heavy flow associated with large blood clots
  • Heavy flow interfering with work or social life
  • Heavy flow requiring the use of both pads and tampons simultaneously

If you have had heavy periods for some time, you may also notice the following because you have become anaemic:

  • Dizziness and fainting
  • Headache
  • Tiredness
  • Pale skin, lips and fingernails
  • A high pulse rate and sensation of a racing heart beat

Major causes of menorrhagia

Hormonal imbalance

This cause of heavy periods is the most common and results from an imbalance in the female hormones oestrogen and progestogen. It is common in teenage girls who have recently started having their periods or in women in their forties who are approaching menopause. Often the menstrual cycle is irregular and less than 21 days in this situation. However, heavy periods due to hormonal imbalance commonly occur at other ages too for a variety of reasons including:

  • Use of some types of birth control medication
  • Some types of ovarian cysts

Endometrial polyps

Polyps (fleshy lumps) can grow in the lining of the womb (endometrium) and become more common from the mid-thirties onwards. They are mostly benign (non-cancerous).

Uterine fibroids

Uterine fibroids are benign muscle tumours that grow in the wall of the womb and cause it to be enlarged.


Adenomyosis is a condition where the womb lining (endometrium) becomes embedded deeper into the wall of the womb than it should be. The womb becomes enlarged and often painful.


Cancers that occur in the lining of the womb (endometrial cancer), the wall of the womb (leiomyosarcoma), neck of the womb (cervical cancer), or the ovaries (ovarian cancer) may all cause irregular bleeding. Persistent abnormal bleeding, or any bleeding after the menopause, should be investigated by a gynaecologist.

​Complications of early pregnancy

If you suspect that you may be pregnant, you should perform a urine pregnancy test as abnormal bleeding may be the result of problems in early pregnancy. If it is positive then you should attend an Early Pregnancy Unit for further investigation.

Unusual causes of menorrhagia

  • Congenital (birth) defects of the womb
  • Medications that thin the blood like warfarin
  • Genetic blood clotting disorders like Von Willebrand’s disease
  • Severely underactive thyroid gland
  • Infection

Read on to learn about how menorrhagia is diagnosed and treated.


Ref: S13