Are they a curse? A celebration of your fertility? A relief that you’re not pregnant (where did that condom go that night?). Something to put up with, the bane of your life, or hardly noticeable? Cause you huge embarrassment when you leak... or huge anxiety because they seem to have dried up for months. Cripple you with pain, diarrhoea and vomiting?

All of the above statements are quite normal and indicate how much periods and the attitudes towards them vary from woman to woman. Normal means that your cycle (time between your periods) can vary from 21-42 days and that the length of your period (the time that you actually bleed can vary from 3-7 days or sometimes longer. The average length of bleed is probably about 5 days with the first couple of days being heavier and often the most painful.

Some lucky women know pretty much to the hour when their period will start and describe their periods as being like clockwork. For most women there is a bit more guesswork, but doctors would view a cycle as being regular even if it changes by as much as a week each month.

Your menstrual cycle is controlled by complex hormonal mechanisms involving sensitive feedback mechanisms between your ovaries, womb and brain. Most women are aware that stress can interfere with your periods, as can other factors such as illness, sudden loss of weight and large amounts of exercise. The commonest hormonal cause of irregular, infrequent periods is the polycystic ovary syndrome. Other hormonal causes include alterations of your thyroid function and much more rarely alteration of the function of the pituitary gland or your ovaries.

What is much more important is whether things have changed for you. So, if it is normal for you to have a cycle that changes by a few days each month, there is no point in worrying about it. But if your cycle becomes very erratic with much more frequent periods, it could signal that something is wrong. Similarly, if you suddenly change to only having periods every 2-3 months, you should seek advice.

Other symptoms to watch for are

  • Bleeding in between your periods
  • Bleeding after sex
  • Increasingly painful periods, in particular, pain that starts days before your periods and lasts much longer through your bleed
  • Pain in your tummy during sex
  • Increased vaginal discharge

Further information



Painful periods (dysmenorrhoea)

This article published on
25 November 2005

Next review date 11/1/2013


Embarrasing stuff
Contraception and pregnancy

Areaof the body

Reproductive system

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