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HealthInfo Canterbury

Heavy periods

Heavy periods (menorrhagia) are very common in women, and usually are not a sign of anything serious – but they can cause a big disruption to your life. Heavy periods can cause tiredness from low iron in your blood, or less commonly, anaemia (low red blood cells).

A woman with a normal menstrual cycle may bleed for up to eight days, with bleeding happening every 25 to 35 days. Most of the blood loss occurs in the first three days.

Heavy bleeding is hard to define, but if you have to change tampons or pads many times a day, avoid going out for fear of an "accident" (flooding), have large clots, or have to get up in the night to change pads, then you almost certainly have heavy bleeding. If you have heavy bleeding with every period this is called menorrhagia. Menorrhagia is more common in women who have just started their periods or are coming up to menopause.

Causes of heavy periods

In most cases we can't find what's causing the heavy bleeding. The woman's uterus, ovaries, and hormones are normal.

Occasionally there is a cause for heavy bleeding. These causes can include: fibroids, endometrial polyps, endometriosis, hormonal problems, pelvic infections, pre cancer, or cancer of the lining of the womb, some medications, and blood clotting problems.

Do I have heavy periods?

It's hard to know whether your periods are especially heavy, so you may want to read up about what is normal and what symptoms suggest your bleeding is heavier than normal. However, if you are concerned about your periods, or if period problems are disrupting your life, you should make an appointment with your general practice team.

Written by HealthInfo clinical advisers. Endorsed by clinical director Obstetrics & Gynaecology, Canterbury DHB. Reviewed November 2016.

In this section

Tests & diagnosis for heavy periods

Managing heavy periods

Treatment options for heavy periods

More information about heavy or irregular periods

Page reference: 36981

Review key: HIHPE-15976