Excessive blood loss during a menstrual period (menorrhagia or flooding) is uncomfortable, distressing and may lead to anaemia and other health problems. In most women a heavy menstrual period it is a constitutional problem in that there is no specific disease or condition causing the problem, but it is the way that their body deals with the monthly hormonal changes. In a few cases though, there is an underlying medical problem. This is more likely if the periods have changed to become heavier over a few months.
The menopause occurs in the late forties and early fifties in most women. Instead of cycling smoothly and evenly through the monthly changes, sex hormone (oestrogen and progestogen) levels start to change suddenly, irregularly and inappropriately. This causes the symptoms of menopause which include irregular menstrual periods that can vary from very light to very heavy, hot flushes, headaches, irritability, personality changes, breast tenderness, tiredness and pelvic discomfort.
Inappropriately high levels of oestrogen being prescribed for hormone replacement therapy may cause heavy periods.
Psychological disturbances (eg. severe stress, shock or anxiety) may affect oestrogen production and irregular heavy periods may follow.
Other causes of menorrhagia include fibroids (hard balls of fibrous tissue that form in the muscular wall of the uterus), cysts in an ovary, ulcers and erosions of the cervix (opening of the uterus into the vagina), endometriosis, a miscarriage (may cause abnormal bleeding before a woman is aware that she is pregnant), an ectopic pregnancy (development of a growing foetus in the fallopian tubes instead of the uterus), salpingitis (infection of the fallopian tubes), hypothyroidism (an underactive thyroid gland) and tumours, polyps or cancers of the uterus or cervix may cause irregular heavy bleeding, that may not be related to the menstrual cycle, but be caused by direct bleeding from the growth.