Heavy periods (menorrhagia)

What are heavy periods?

The correct medical definition of heavy periods is the passage of more than 80ml of blood each period. It is seldom realistic or practical, however, to actually measure the blood loss and so doctors rely on the woman's description of her period.

Periods are considered heavy when:

• a woman bleeds for more than 8 to 10 days, especially if this is repeated month after month.


• a woman bleeds so much that it is difficult for her to attend her job. She may be forced to plan her holidays and leisure time according to the timings of her period.


•  the bleeding is continuously so heavy that the woman becomes anaemic.


•  the presence of other than small clots for more than one or two days suggests heavy periods.


•  'flooding' describes the sudden, unexpected onset of periods, like turning on a tap, and indicates heavy periods.

The signs and symptoms of menorrhagia may include:

• Menstrual flow that soaks through one or more sanitary pads or tampons every hour for several consecutive hours
• The need to use double sanitary protection to control your menstrual flow
• The need to change sanitary protection during the night
• Menstrual periods lasting longer than seven days
• Menstrual flow that includes large blood clots
• Heavy menstrual flow that interferes with your regular lifestyle
• Constant pain in your lower abdomen during menstrual periods
• Tiredness, fatigue or shortness of breath (symptoms of anemia)

What causes my periods to be heavy?

Most women with heavy periods have a normal womb and normal ovaries.

Women using an intra-uterine contraceptive device may experience heavy periods from the time the IUCD (coil) was inserted. This may or may not settle after a few months.

Women who are taking the combined contraceptive pill generally have lighter, less painful periods than usual. Such women may sometimes find their periods become heavier again when they stop taking the pill. This increase in flow usually means the woman is returning to her normal menstrual cycle pattern. The pill itself does not cause period problems.

Other causes include:

• the hormones controlling your periods,
• changes in the blood concentration of natural chemicals called prostaglandins, which help to close off the blood vessels,
• polyps, which are small benign swellings of the womb lining,
• endometriosis,
• fibroids, which are benign (non-cancerous) growths of fibrous tissue within the wall of the womb,
• pelvic inflammatory disease, fibroids, polyps, (for details, see below);
• cancer in rare cases.

In most cases, however, there will be no obvious cause.