So what is 'typical menstruation'? There appears to be lots of variation, not only between different women but also from one cycle to the next in one woman. Many research studies have looked at this and a set of criteria have been set out by an international group of experts in menstruation. There are four different criteria by which menstruation can be measured:Duration (how long your period lasts) 4.5 to 8 daysFrequency (how often it comes) every 24 to 38 daysRegularity (how regular it is) changes by 2-20 days over 12 monthsVolume (how heavy it is) 5-80ml of bloodThe measures above are really useful for research purposes but may not be very practical for women. Especially the volume figures – not so easy to measure in reality! Much more important is the impact that menstruation has on your life. Flooding through your clothes during the day and/or not being able to go to work or school because of heavy or painful periods is not 'normal'.If your menstruation is having a negative impact on your life you should seek help. Image HTML Cookies on the University of Edinburgh Website Your consent is needed for content delivered by non-University companies. Viewing this content will result in cookies being set on your device and will result in some information about your visit being saved. By accepting this you agree for this information to be shared with these non-University companies. Accept and view Image Webinar graphic from the ALLIANCE and Scottish Government’s webinar ‘Periods are normal – but what is a normal period?’. Illustration by Clare Mills from Listen.Think.Draw.View the full webinar here. This article was published on 2024-09-10