How your periods change during perimenopause

The average length of time for perimenopause is around 4 years, but it is different for each person¹. Once you've gone through 12 consecutive months without a period, you've officially reached menopause and the perimenopause period is over.

During perimenopause, your levels of the hormones oestrogen - one of the main female hormones - and progesterone rise and fall. This affects your menstrual cycle.

What to expect during perimenopause

Premenstrual symptoms

Dr Jayne Forrester-Paton, a GP and British Menopause Society accredited menopause specialist at Your Menopause Doctor, says it’s very common for your periods to gradually change as you enter perimenopause.

“One of the earliest signs of perimenopause can be a gradual worsening of premenstrual symptoms (PMS), these can be physical and/or psychological,” she says. “For example, you may experience worsening headaches, bloating, breast tenderness and mood changes in the days leading up to a period. For some women, the duration of PMS lengthens and they have less 'good' days each month.”

Forrester-Paton says some women may notice night sweats or hot flushes just in the days leading up to their period. “Periods may still be regular at this stage,” she adds.

Irregular periods

As you progress through perimenopause, your periods may become more irregular than usual. “A classic pattern is for periods to get closer together before gradually becoming spaced further and further apart, until they eventually stop altogether,” says Forrester-Paton.

Heavier or lighter periods

It is also common for periods to become heavier as the gaps between them widen. You may also experience spotting between periods.

“Some people may experience flooding or clots for the first time,” she says. “However, as with everything related to the menopause and perimenopause, the experience varies widely from person to person. Some will experience periods abruptly stopping with little warning, or others lighter and easier to manage periods.”

Anovulatory cycles

An anovulatory cycle is a menstrual cycle in which ovulation - the release of an egg from the ovaries - doesn’t happen. Anovulation is often due to hormonal imbalances and can occur during perimenopause. Signs of an anovulatory cycle vary, but can include - irregular periods, missing periods, unusually heavy or light bleeding, or infertility. Sometimes, though, there are no obvious signs.

Blood colour changes

Your menstrual blood may also look different and sometimes, it can appear darker or brown. Menstrual blood appears red when it’s fresh and has left the body quickly, but it can look darker if it is old, oxidised blood that has been in the uterus for longer. This can happen during perimenopause because hormonal imbalances mean the uterine lining breaks down differently.

Discharge changes

You may notice changes in the consistency of your discharge, which may become thinner or thicker².

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How to manage changes to your period

It can help to track your period on a calendar, so you can see how your menstrual cycle is changing. Note down any other symptoms, like unusual bleeding or pain - so you can show your doctor if you need to.

Keeping tampons, sanitary towels and a change of underwear in your bag can be a good idea if you’re not sure when your period will arrive, or how heavy it will be. It’s also helpful to have over-the-counter painkillers like paracetamol or ibuprofen on hand too. You can also buy period-proof underwear, which will absorb unexpected leaks or spotting.

When to see a doctor about changes in your period

Speak to your doctor

It’s important not to ignore changes to your bleeding pattern or flow and to discuss this with your GP to ensure any concerning causes can be ruled out," says Forrester-Paton.

If you are worried about your menstrual cycle or any other symptoms, it's best to speak to your doctor to be safe.

If you’ve missed a period and it’s possible you could be pregnant, you should take a pregnancy test. Even if you’re in perimenopause, you can still ovulate and become pregnant. If you are under 50, you can still get pregnant up to 2 years after your last period and if you are over 50, you can still get pregnant up to 1 year after your last period.

Further reading

1. Delamater et al: Management of the perimenopause.

2. Henn et al: Vaginal discharge reviewed - the adult premenopausal female.