Having absent periods either means you have stopped having periods or haven’t started them by the time you are 14-16 years old.

The medical name for absent periods is amenorrhoea.

In many cases, absent periods are not a cause for concern because some girls simply start having periods later than usual and it is normal for your periods to stop at certain points.

For example, your periods will stop while you are pregnant or breastfeeding, or after the menopause. Some types of contraception can also cause you to temporarily stop having periods.

However, absent periods can sometimes be a sign of an underlying medical condition, such as:

• polycystic ovary syndrome (PCOS) – a condition which can mean your ovaries do not regularly release an egg (ovulate)
• hypothalamic amenorrhoea – where the part of the brain that regulates the menstrual cycle stops working properly (thought to be triggered by excessive exercise, excessive weight loss and stress)
• hyperprolactinaemia – where a person has abnormally high levels of a hormone called prolactin in their blood
• premature ovarian failure – where the ovaries stop working properly in women who have not yet reached the age of natural menopause (usually from 50 years of age)

Read more about the causes of absent periods.

When to seek medical advice

You should see your GP if you're worried about any problems with your periods, so they can try to determine the cause.

Depending on what your GP thinks may be causing your absent periods, you may be referred to a specialist for further investigation and any necessary treatment.

Read more about diagnosing absent periods.

Who is affected

Stopping having periods after previously having them, known as secondary amenorrhoea, is relatively common - it's estimated to affect around 1 in 25 women 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 by the expected age, known as primary amenorrhoea, is much less common. It's estimated to affect 1 in every 300 girls and women.

How absent periods are treated

The treatment for absent periods will depend on the cause.

For example, PCOS can often be controlled using hormonal treatments, and women with hypothalamic amenorrhoea will often start to have regular periods if they cut down on exercise and reach a healthy weight.

In some cases, your doctors may recommend waiting to see if your periods return or start on their own.

Sometimes your periods cannot be restored with treatment, as is usually the case with absent periods caused by premature ovarian failure.

Read more about treating absent periods.