Heavy periods, also known as menorrhagia, are the leading cause of discomfort among women of childbearing age in the UK.

It is menstrual blood loss which interferes with a woman's physical, emotional, social, and material quality of life. It’s estimated that around 6.5 % of women between the ages of 12 and 51 experience heavy periods.

What defines heavy periods?

The typical woman’s period lasts for around 5 days, during which time she loses around 30-40 ml (around 2 tablespoons) of blood. The definition of heavy periods varies between women, and the amount of blood you lose each month will depend on your own individual hormone levels.

In general though, heavy periods are defined as one or more of the following:

  • Losing more than 80 ml of blood during your period.
  • Having a period that lasts longer than 7 days.
  • Passing large clots of blood during your period.

What causes heavy periods?

Having heavy periods does not always mean there is something seriously wrong with you. In other cases though, they can indicate more serious gynaecological conditions including:

  • Hormonal imbalance: heavy periods are sometimes caused by high levels of oestrogen in the body, or by excessive levels of the hormones that are responsible for your uterus lining being shed every month.
  • Endometriosis: cells of the uterus lining grow outside of the uterus elsewhere in your abdomen or body.
  • Fibroids: benign growths that occur in the abdominal cavity in and around the uterus. They can vary in size from being microscopic to taking up large amounts of space in your abdomen.
  • Pelvic inflammatory disease: this is caused by a long-standing bacterial infection that has spread to the organs of the upper genital tract such as your fallopian tubes, ovaries and uterus.
  • Polycystic ovary syndrome (PCOS): a hormonal imbalance causes the ovaries to produce small cysts instead of eggs, causing a range of symptoms, including excessive hair and infertility. Find out more about polycystic ovary syndrome. [Link to interview page with Colin Davis in the gynaecology section.]
  • The insertion of an intrauterine contraception device (IUD) can also result in heavy periods.
  • In rarer cases, heavy periods can be caused by blood clotting disorders, liver or kidney disease, problems with the thyroid gland, or endometrial cancer.

Complications caused by heavy periods

If they are severe, heavy periods can cause physical and emotional discomfort and this can disrupt your normal routine. Heavy periods can also result in anaemia, which is an iron deficiency in your body. If you lose blood between periods, you experience bleeding after you have had sex and you have heavy bleeding during your period, this may mean you have a more serious condition and you should consult your doctor.

You should also seek medical advice if you experience the following:

  • Periods that last an abnormally long time (more than half the month).
  • Feeling constantly tired.
  • Feeling faint, dizzy or light-headed.
  • Not being able to sleep well.
  • Finding it hard to catch your breath.

Tests to find out why you are having heavy periods

If you are experiencing heavy periods, your doctor may give you tests to find out their cause. The following tests can be performed:

  • Ultrasound scan: a scan that uses sound waves to check for fibroids and endometriosis.
  • Pelvic examination: a physical inspection of your vagina and cervix to check for abnormalities in the pelvic region.
  • Biopsy: taking a small sample of tissue from inside the uterus to check for abnormalities using a microscope.
  • Laparoscopy: an endoscopic camera, called a laparoscope, is placed into your abdomen so that your gynaecologist can check the uterus, fallopian tubes and ovaries, and can also look for signs of disease in other organs.
  • Measuring menstrual blood loss: you may be asked to weigh every tampon or sanitary pad after it has been used to estimate the actual amount of blood you are losing.
  • Blood tests: your blood will be tested to see if you have iron-deficiency anaemia; this is more common in women who have been having heavy periods for some time.