Abnormally heavy or prolonged menstrual bleeding is also called 'abnormal uterine bleeding'. We sometimes use this general term to describe bleeding that does not follow a normal pattern, such as spotting between periods. It used to be referred to as menorrhagia, but this term is no longer used medically.
On average, a typical woman passes around 40 ml of blood during her menstrual period, which lasts around four to seven days. For some women, however, bleeding may be excessively heavy or go on for longer than normal.
A woman may have 'chronic' heavy or prolonged bleeding (for more than six months) or it may be 'acute' (sudden and severe). In most cases, the causes of abnormal menstrual bleeding are unknown. See your doctor about any abnormal menstrual bleeding.
Symptoms of abnormal uterine bleeding
- bleeding for more than eight days
- heavy blood loss during the menstrual period – for example, soaking through one or more sanitary pads or tampons every hour for several hours in a row
- needing to change your pad or tampon during the night
- have to change or restrict your daily activities due to your heavy bleeding
- bleeding or spotting between periods (intermenstrual bleeding)
- cramping and pain in the lower abdomen
- any vaginal bleeding after menopause.
If you think you may be experiencing heavy menstrual bleeding, you may find it useful to keep a pictorial blood loss assessment chart – this can help you give your doctor an idea of how heavy your period is.
Causes of abnormal uterine bleeding
While in many cases it is not possible to determine the exact cause, there are a number of reasons a woman may experience abnormal uterine bleeding. Some of the known causes of abnormal uterine bleeding include:
- spontaneous miscarriage in pregnancy
- ectopic pregnancy – lodgement of the fertilised egg in the slender fallopian tube instead of the uterine lining
- hormonal disorders – conditions such as hypothyroidism (low levels of thyroxine), polycystic ovarian syndrome (PCOS) and hyperprolactinemia can disrupt the menstrual cycle
- ovulatory dysfunction – this is when the ovary does not release an egg each month. Most commonly, this occurs at either end of a woman's reproductive years, either during puberty or at menopause
- endometriosis – the cells lining the uterus (endometrial cells) can travel to, attach and grow elsewhere in the body, most commonly within the peritoneal cavity (including on the outside of the uterus or on the ovarian surface)
- infection – including chlamydia or pelvic inflammatory disease (PID)
- medication – may include anticoagulants, which hinder the clotting ability of the blood; phenothiazides, which are antipsychotic tranquilisers; and tricyclic antidepressants, which affect serotonin uptake
- intrauterine device (IUD) – is a contraceptive device that acts as a foreign body inside the uterus and prompts heavier periods
- hormonal contraceptives – may include the combined oral contraceptive pill, injections of a long-acting synthetic progesterone, a rod containing slow-release progesterone (implanted in the upper arm), or intrauterine system devices (progesterone-releasing contraceptive devices inserted into the uterus). The progesterone-only treatments commonly cause spotting
- hormone replacement therapy – used as a treatment for menopausal symptoms
- fibroids – benign tumours that develop inside the uterus
- polyps – small, stalk-like projections that grow out of the uterus lining (endometrium). Polyps may be associated with fibroids
- bleeding disorders – may include leukaemia and Von Willebrand disease
- cancer – most uterine cancers develop in the lining of the uterus, though some cancers grow in the muscle layers of the uterus. They are most common after menopause.
Diagnosis of abnormal uterine bleeding
The diagnosis and identification of potential causes of abnormal uterine bleeding involves a number of tests including:
- general examination
- medical history
- menstrual history
- physical examination
- cervical screening test
- blood tests
- vaginal ultrasound
- endometrial biopsy.
Treatment for abnormal uterine bleeding
Treatment will depend on the cause, but may include:
- medication – such as prostaglandin inhibitors, hormone replacement therapy or antibiotics
- dilatation and curettage (D&C) – involving dilation and gentle scraping of the cervix and the lining of the uterus
- change of contraception – it may be necessary to explore methods of contraception other than the IUD or hormones
- surgery – to remove tumours, polyps or fibroids or to treat ectopic pregnancy
- treatment of underlying disorders – such as hypothyroidism or a bleeding disorder
- hysterectomy – the removal of the entire uterus is a drastic last resort, generally only considered for treatment of abnormal uterine bleeding when a serious disease, such as cancer, is also present.
Where to get help
This page has been produced in consultation with and approved by:
Hudson Institute of Medical Research
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