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 not had surgery to remove part or all of their womb
- have not yet gone through the menopause, which normally happens in the late 40s or early 50s
The medical name 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 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 call this primary amenorrhoea).
- You previously had regular periods but have now not had a period for six months in a row (doctors call this secondary amenorrhoea). This is the most common type of absent periods.
What causes absent periods?
If you've never had a period
Possible 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 reproductive system
If you used to have periods but they've stopped
A 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 (it's 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 thyroid or underactive thyroid
Read more about the potential causes of absent periods.
Treating absent periods
The treatment for missing periods will depend on the 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 absent periods.
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.
It is more common in teenage girls and younger women, and can be much more common 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 also have information on:
