Not having regular periods is usually considered a cause for concern in girls and women who:
- have gone through puberty (which normally happens around the age of 12-13)
- are not pregnant
- have an intact womb (have not had surgery to remove part or all of the womb)
- have not yet gone through the menopause (which normally happens in the late 40s or early 50s)
The medical term for absent or missing periods is amenorrhoea.
When to seek medical advice
Missing periods can be a sign of an underlying health problem. It is recommended that you visit your GP if:
- you have not had a period by the time you are 14 and you also show no other sign of sexual development (such as breast growth and pubic hair) or you have not had a period by the time you are 16 but other signs of sexual development are normal (doctors refer to this as primary amenorrhoea)
- you have previously had regular periods but have now not had a period for six months in a row (doctors refer to this as secondary amenorrhoea and it is the most common type of amenorrhoea)
What causes absent periods?
Potential causes of primary amenorrhoea include:
- delayed periods – some girls just take longer than average to have their first period
- problems with the development of the female reproductive system
An underlying health problem is usually the cause of your periods stopping. The five most common conditions causing secondary amenorrhoea are:
- polycystic ovary syndrome (PCOS)
- hypothalamic amenorrhoea – where the part of the brain that regulates the menstrual cycle stops working properly (thought to be triggered by excessive exercise, weight loss and stress)
- hyperprolactinemia – where a person has abnormally high levels of a hormone called prolactin in their blood
- the ovaries stopping working properly (ovarian failure), even though the woman has not yet gone through the menopause
- hormonal conditions such as having an overactive or underactive thyroid gland
Read more about the potential causes of amenorrhoea.
Treating absent periods
The treatment for missing periods will depend on the underlying cause.
For example, PCOS can often be controlled using hormonal treatments, and women with hypothalamic amenorrhoea will have regular periods if they cut down on exercise and eat more.
However, some causes of absent periods, such as ovarian failure, cannot be successfully treated and the woman will become infertile.
Read more about the treatments for amenorrhoea.
Who is affected?
Secondary amenorrhoea is relatively common. It is estimated that around 1 in 25 women will be affected by absent periods at some point in their lives.
Teenage girls and younger women are more widely affected, and this figure can be much higher in certain groups, such as professional athletes, dancers and gymnasts.
Not starting your periods is much less common, affecting an estimated 1 in every 300 girls and women.
If you have other problems with your periods, we have information on:
irregular periods
heavy periods
painful periods
