Heavy or excessive menstrual bleeding can be a distressing problem, and is one of the most common reasons for women to visit their GP. 1 in 3 women describe their period as heavy and 1 in 20 women consult their GP every year about this problem.
In more than half of cases heavy menstrual bleeding has no obvious cause. However, it is sometimes related to the presence of organic disease. Known common causes include:
- Fibroids: benign enlargements of muscle in the wall of the womb
- Endometrial polyps: benign outgrowths of the lining of the womb
- Endometriosis: misplaced lining of the womb
- Pelvic inflammatory disease: infection of the pelvis
- Polycystic Ovarian Syndrome (PCOS)
- Cancer of the womb lining (Endometrial Carcinoma)
For more information on these conditions, see the relevant WHC factsheets. Other causes of irregular and heavy bleeding may be:
- Abnormal hormone cycles
- Blood clotting disorders (rare)
- Thyroid gland problems – (also rare)
- Intra-uterine contraceptive devices (IUCDs)
- Warfarin or a similar blood thinning medicine
- Some medicines used in chemotherapy
Oral contraceptive pills make most women’s periods lighter. Hence, if you stop taking contraceptive, it may appear that your menstrual periods have become heavier, when they are really returning to what is normal for you.
Symptoms and effects
The average total amount of blood lost during a period is 35ml – about half a tea cup.
Bleeding is considered abnormal when more than 80ml is lost, because if you are losing more than 80 ml during periods, you are at a risk of developing anaemia. Some women lose much more blood. Bleeding more than a litre each month has been recorded, but this is very unusual. Regular heavy periods with no other bleeding during the cycle are not normally associated with significant disease in young women. Irregular heavy periods and bleeding between periods or after sexual intercourse may indicate a serious condition. Other symptoms to watch out for include prolonged periods, tiredness, light headedness, poor sleep patterns and breathlessness. Although in most cases irregular periods do not indicate a serious condition, it is always wise to seek advice from your GP.
It is often not easy to know whether your periods are heavier than other women or not. Measuring blood loss during menstrual period is not easy either. Hence blood loss during menstrual period is considered heavy if it causes one or more of the following:
- Flooding through clothes
- You pass large clots
- You need frequent change of sanitary towels or tampons
- You need double sanitary protection
- Heavy periods occurring every month which stops you doing routine activities such as going out, working or shopping
In cases of abnormal bleeding it is important to discover if there is any underlying problem in the pelvis. This is done by means of a simple pelvic examination. The doctor inspects the vulva, vagina and cervix (neck of the uterus) to make sure there is no abnormality that could account for the bleeding. At the same time the doctor can check for signs of other conditions such as fibroids or endometriosis. A blood test is often performed to check for anaemia.
Sometimes further tests are needed.
These may include:
- Transvaginal ultrasound scan: This is useful if any swelling is found on examination of the pelvis
- Endometrial biopsy: A sample of the lining of uterus is taken and examined under a microscope
- Hysteroscopy: A thin telescope is passed through the cervix so that the uterine cavity can be examined
- Internal swabs: to check for infections
Keeping a menstrual diary may help you and your doctor to understand the pattern of your menstrual period and decide what test or treatment may be helpful. Keeping a menstrual diary is also likely to help in monitoring the effects of treatment.
Treatment options depend on the type and duration of abnormal bleeding, the presence of specific disease or condition, your age, and desire for further pregnancies. Treatment can be medical or surgical.
Once a serious condition has been excluded, you may choose not to have any treatment especially if symptoms are not significantly affecting your health or quality of life.
Medical treatments include taking medicines which act either by reducing levels of prostaglandins, or by affecting the blood clotting process that takes place in the uterus during periods. A commonly prescribed drug is tranexamic acid. This is taken in tablet form, and helps to reduce blood loss but does not reduce the duration of bleeding. Hormones such as progestogens or the combined oral contraceptive pill can also be prescribed, for regularising irregular periods and reducing the amount of blood loss. An intra-uterine progestogen releasing system, has been shown to be very effective in reducing the amount of blood loss, and indeed, periods may almost disappear after six months. The device is effective for five years. Hormone replacement therapy may benefit women nearing the menopause who also have menopausal symptoms, but should not be used purely to control bleeding. In cases of severe bleeding, it may be necessary to administer a drug which stops your ovaries working (causing a temporary menopause) and your periods may stop altogether.
It was believed for many years that a curettage – scraping out the uterine lining – reduced bleeding, but now it is known that this procedure does not have any long term beneficial effect. The definite and most effective treatment for abnormal bleeding is removal of the uterus, or ‘hysterectomy’. Endometrial ablation is a technique which involves local destruction or removal of the uterine lining. However, it is not suitable for all women. For more information on these procedures see our related factsheets: Hysterectomy and Endometrial ablation.