Irregular and Heavy Periods

This article on irregular and heavy periods has been written in plain English by a Consultant Gynaecologist. It will be of help to any woman who is wondering whether her menstrual period is normal or whether it may be a sign of something more serious.



Irregular and heavy periods are amongst the most common gynaecological problems that trouble women during their childbearing years.  Published studies report that between 4% and 50% women suffer from heavy periods; this large variation is probably due to cultural differences and the way that ‘heavy periods’ are defined or measured. However, it is likely that approximately one in eight to ten women experience heavy periods.

What is a normal period?

Periods, (also defined as menstruation, menses or menstrual periods), are a woman’s monthly bleeding from her womb (uterus) as a result of the cycle of hormonal changes. A period contains blood, tissue (lining of the womb) and fluid from inside the womb. Although periods are usually described as ‘monthly’ bleeds, there is actually a huge variation in how frequently they occur.  There are no certain rules, but it is generally accepted that periods that come every 22 to 35 days are within the normal range. The duration of bleeding varies between three to eight days in most women, with an average of four to five days bleeding. The length of the cycle and duration of bleeding tend to decrease with age but, in contrast, blood loss tends to increase. Irregular periods are more common in younger women and periods become more regular with advanced age up until premenopausal years when irregularity becomes more of a problem again.

What is a heavy period?

The published research suggests that heavy periods are when a woman loses more than 60 to 80 millilitres of blood with menstruation.  However, this definition is unhelpful as it is impractical to measure the blood loss in real life.  For this reason it is better to define periods as heavy when they interfere with a woman’s physical, social or emotional quality of life. In other words, the definition of heavy periods (or menorrhagia to use the medical term) is a subjective symptom as experienced by individual women.

What is abnormal vaginal bleeding?

Periods are generally considered abnormal if they are excessively heavy and if they are irregular outside their usual pattern. In addition, vaginal bleeding is considered abnormal if it occurs in between periods (also known as intermenstrual bleeding), after sexual intercourse (postcoital bleeding) or if a woman restarts bleeding after the menopause (postmenopausal bleeding). Irregular periods, bleeding in between periods or after sex, or bleeding after the menopause are all symptoms that are more likely to indicate a potential underlying medical problem and they require investigation.

For further information on the author of this article, Consultant Gynaecologist, Mr Ertan Saridogan, please click here.
A fluid that transports oxygen and other substances through the body, made up of blood cells suspended in a liquid. Full medical glossary
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The basic unit of genetic material carried on chromosomes. Full medical glossary
Between menstrual periods. Full medical glossary
Relating to the menopause, the time of a woman’s life when her ovaries stop releasing an egg (ovum) on a monthly cycle. Full medical glossary

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Full medical glossary
Heavy or prolonged menstrual periods. Full medical glossary
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