Perimenopause periods – why they change and how to cope

30th November, 2021 • 8 min read
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One of the signs of perimenopause (the stage leading up to the menopause) is changes to your periods and normal period cycle. This can be inconvenient and worrying - especially if you've been used to having a regular cycle up until now.

As you approach the menopause (when your periods stop altogether and you can’t get pregnant naturally anymore), your ovaries produce less of the hormones estrogen and progesterone.

This can cause many symptoms including hot flashes, mood changes, poor sleep and changes to your periods, like their frequency. You may find that your periods are getting closer together, they become more irregular or happen less often, and they may become heavier or lighter, among other changes.

These perimenopause period changes are usually nothing to worry about, but if, for example, you’re having a period a lot more frequently than normal like a period every two weeks, there could be an underlying medical problem. If this is your experience then it's best to see a doctor.

Read on to discover what can cause changes to your periods during perimenopause, how to manage this and when you might need medical help.

Why is my menstrual cycle getting shorter?

The first sign that you’ve started

the menopause
(usually between age 45 and 55) is usually a change in the normal pattern of your periods.

Your menstrual cycle starts on the first day of your period and ends the day before your next period starts – but its length differs from person to person. A menstrual cycle of 21 to 40 days is considered a normal range, but often, around 28 days is seen as more usual. However, the latest research suggests that fewer than 20% of women tend to have a 28-day cycle. This is why you need to get to know your own body to work out what’s normal for you.

When you have

irregular periods
, the length of your menstrual cycle keeps changing, either starting earlier or later than it normally would have.


, your oestrogen levels go down as you start ovulating (when your ovaries release an egg) less frequently, which makes the lining of your womb thinner than usual. This estrogen deficiency can cause your periods to become lighter than normal and shorter (lasting fewer days than usual), so your menstrual cycle may last 2 or 3 weeks rather than the 4 or 5 weeks it usually does, for example. As a result, your periods can become closer together.

These hormonal changes can also cause heavier periods, or you may not have them at all for months on end.

Menopausal symptoms like irregular periods,

hot flushes
night sweats
vaginal dryness
poor sleep (insomnia)
mood swings
may happen months or even years before your periods stop. But everyone is affected differently by menopausal changes and some people may even have normal periods up until the time they stop altogether.

Read more about

unusual menopause symptoms
to look out for,
menopause brain fog
menopause joint pain

Find useful information on other areas of menopause with our

complete Guides

What else causes irregular periods?

In perimenopause irregular periods are a common sign but there there are a number of reasons why your periods may become irregular – including more or less frequent. This can be normal for you but, sometimes, an abnormal bleeding pattern may be a sign of something more serious and it’s best to

see a doctor

Other than the menopause, common causes of irregular periods, including less and more frequent bleeding, include:

Other less common causes of frequent bleeding include cancers such as

womb (endometrial) cancer
cervical cancer

Is it normal to have a period lasting two weeks?

As you go through perimenopause, your periods may last longer and become further apart. Evidence shows that having periods that last 8 days or longer is common when you’re going through this natural stage in your life.

You may also bleed more heavily if you’re obese (if your

body mass index, or BMI
, is 30 and over) or have a fibroid, and as you approach the time when your periods stop altogether.

So, for some people, it may be normal to bleed for 2 or 3 weeks during the perimenopause, but it’s best to see a doctor for their advice, as they may want to do some tests to make sure there's nothing else causing your longer periods, and that you’re not losing too much blood and becoming

. Read below for when else to see a doctor about periods in perimenopause.

When to see a doctor about perimenopause periods

When you’re going through perimenopause, it’s normal to experience changes to your periods, but sometimes, an abnormal bleeding pattern may be a sign of an underlying issue that needs medical attention.

Call an ambulance or go straight to an emergency department if you’re bleeding from your vagina and you have:

  • severe tummy (abdominal) pain
  • very heavy bleeding that won’t stop – that is, you’re having to change your sanitary products every hour, or are passing blood clots larger than 2.5cm (about the size of a 10p coin)
  • tummy (abdominal) pain that won’t go away and you think you may be pregnant (this may be a sign of a
    or an
    ectopic pregnancy
  • you feel tired and lack energy (lethargy), you’re short of breath, have heart palpitations and a pale complexion (these may be signs of
  • a fever, you feel faint or very unwell, or have any other signs of

Although it's common during the perimenopause and usually nothing to worry about, sometimes, bleeding can point to an underlying medical problem, so see a doctor as soon as possible if you're bleeding from your vagina and:

  • it’s lasted longer than 7 days
  • it’s happening every 2 to 3 weeks or more frequently
  • it’s happening during or after sex, or between your periods
  • you haven’t had a period for 1 year or more before it started
  • you could be at risk of an STI
  • you have
    abnormal vaginal discharge

Also, see a doctor if your periods have become unusually heavy for you, or they’re painful.

How to manage irregular periods during perimenopause

Treatment for irregular or frequent bleeding depends very much on what’s causing it. If you’re bleeding frequently, you may need some tests to see if there's any other underlying medical reason for your bleeding. For example, a doctor may want to do an

ultrasound scan
to check the thickness of your womb, some
blood tests
or a test for STIs.

If an underlying cause is found, this may need medical treatment that a doctor will advise you on. But, if your bleeding problems are caused by the perimenopause alone, there are some things you can do to manage them yourself.

For example, if you have short, unpredictable periods, consider wearing daily protection such as panty liners, pads or period pants (the environmentally-friendly option).

Painful or heavier periods can be treated with some

non-steroidal anti-inflammatory drugs (NSAIDs)
, including
that you can get in a pharmacy or supermarket, or with stronger NSAIDs that you would need to get from a doctor. Speak to a pharmacist or doctor first about how to safely get and use these medicines.


Mirena coil
is often recommended as a treatment for controlling heavy periods during the perimenopause – and can be used as part of

Hormonal medications like the

combined oral contraceptive pill
(commonly called the pill) or HRT can also sometimes be used to regulate bleeding, depending on your age and other underlying medical conditions. HRT may be especially helpful if you have other menopausal symptoms.

Some types of HRT allow a ‘withdrawal bleed’, which happens every month like a period. These are usually given if your periods haven't stopped. Other types usually don’t cause any bleeding and are given if your periods have stopped. However, both types can cause some unpredictable bleeding, especially in the first 3 months of using them. If this happens, you may need some more tests, or to have your HRT type or dose changed.

If you normally have a regular cycle, are sexually active and miss a period, consider taking a pregnancy test to make sure your irregular periods are due to perimenopause and not pregnancy.

Your health questions answered

  • Is ovulation bleeding a sign of menopause?

    Ovulation bleeding is light bleeding or spotting that happens when you ovulate, usually in the middle of your period cycle. As you approach menopause, you’re less likely to ovulate, as your egg reserves reduce and eventually disappear. So, although ovulation bleeding isn’t usually a sign of menopause, any changes in your periods – including bleeding more frequently or in the middle of your cycle – can be. Mid-cycle bleeding can have lots of different causes, so it’s best to get it checked out by a doctor, especially if you’re already menopausal (your periods have stopped altogether) and you’re bleeding or even spotting.

    Dr Roger HendersonClinical writer
    Answered: 30/11/2021

Key takeaways

  • the hormonal changes that occur during the perimenopause can cause a wide range of symptoms including changes to your periods
  • perimenopause can cause your menstrual cycle to be shorter or longer than normal, or your periods to be heavier or lighter, among other changes
  • other medical conditions unrelated to the perimenopause can cause irregular periods too, including pregnancy and PCOS
  • sometimes, an abnormal bleeding pattern may be a sign of an underlying issue that needs medical attention
  • hormonal medicines like the combined contraceptive pill or HRT can sometimes be used to regulate irregular periods

Important: Our website provides useful information but is not a substitute for medical advice. You should always seek the advice of your doctor when making decisions about your health.