What is perimenopause? Symptoms and how long it lasts

What does perimenopause mean?

Perimenopause is the transition before natural menopause (The Menopause Society, Perimenopause). The prefix “peri” means “around,” so the word describes the years surrounding menopause. Menopause itself is a single point in time: 12 months in a row without a period, with no other cause or medical intervention (Hacettepe HSAD, 2024; NICE NG23, 1.3.1). You only know that your last period really was the last one by looking back, once 12 months have passed. The time after that is called postmenopause, meaning after menopause (NHS, Symptoms).

The NHS sums up the process briefly: as hormone levels fall, periods change and eventually stop; this usually happens between the ages of 45 and 55, but it can happen earlier (NHS, Menopause and perimenopause).

What is changing in your body during perimenopause?

The hormone estrogen made by the ovaries starts to fluctuate from your 30s and 40s (ACOG, FAQ047). This fluctuation is not a straight decline. Some months hormone levels run high, some months low. The STRAW+10 working group notes that in the late transition hormone levels swing widely and cycles without ovulation become more frequent (Harlow et al., 2012).

This is why symptoms can come and go in perimenopause. One month everything may be fine, and the next you may have hot flashes, sleep problems or a very different period. These ups and downs are a natural part of the process.

At what age does perimenopause start, and how long does it last?

Studies in Türkiye put the average age at menopause at 47–49; worldwide, a range of 45–55 is usual (HSGM; Hacettepe HSAD, 2024). In the US the average age at menopause is 51 (ACOG, FAQ047). The Turkish Society of Obstetrics and Gynecology (TJOD) notes that the transition can begin from the 40s onward with irregular bleeding, hot flashes, sweating and psychological changes (TJOD).

There is no single answer for how long it lasts. According to STRAW+10, the late transition stage lasts 1–3 years on average, and symptoms such as hot flashes are most common in this stage (Harlow et al., 2012). Sources give different ranges for the total duration of symptoms. The NHS says symptoms usually last 7–9 years, sometimes longer (NHS, Symptoms). The Turkish Ministry of Health’s Public Health Directorate (HSGM) says they can usually last 1–2 years, sometimes stretching to 5–10 years (HSGM). In the US SWAN study, which looked at data from 1,449 women, frequent hot flashes and night sweats lasted a median of 7.4 years in total; the duration was longer in women whose symptoms started early (Avis et al., 2015).

Periods stopping before age 40 is a separate situation. Hacettepe University’s Department of Public Health calls this “early menopause”; NICE deals with this age group under a separate heading and recommends not deciding based on a single blood test (Hacettepe HSAD, 2024; NICE NG23, 1.7).

Stages of perimenopause: what is your cycle telling you?

The international STRAW+10 classification divides the transition into stages based not on hormone tests but on the pattern of your menstrual cycle (Harlow et al., 2012):

• Early transition: The lengths of two consecutive cycles differ by 7 days or more, and this difference happens again within 10 cycles after the first irregular one. For example, one cycle lasts 26 days and the next 34.
• Late transition: You have no period for 60 days or longer.
• Postmenopause: No period for 12 months after the last one.

The Menopause Society also explains that cycles may get a little shorter at first, and that as the transition goes on their length can vary by 7 days or more (The Menopause Society, Perimenopause). You can see which stage your own cycle pattern looks like with a short quiz; the result is not a diagnosis.

What are the symptoms of perimenopause?

According to the NHS, one of the first signs of perimenopause is usually a change in your periods: they may come more or less often, and bleeding may get lighter or heavier (NHS, Symptoms). Hot flashes and night sweats are the most commonly reported symptoms; in a large US study, up to 80 percent of women had them at some point during the transition (The Menopause Society, Perimenopause).

Other common symptoms include trouble sleeping, palpitations, headaches, joint and muscle aches, mood changes, anxiety, memory and concentration problems, vaginal dryness and urinary complaints (NHS, Symptoms; HSGM). The NHS also stresses that symptoms can change shape over time: hot flashes may be the main problem for a while, then give way to low mood or anxiety (NHS, Symptoms). For the full list of symptoms and a detailed explanation of each, see menopause symptoms.

Can a test tell you you’re in perimenopause?

Usually not. NICE considers new hot flashes together with a change in the menstrual cycle, in otherwise healthy people aged 45 and over, enough to count as perimenopause without a lab test (NICE NG23, 1.3.1). The same guideline recommends not using tests such as AMH (a hormone that reflects egg reserve), estradiol, antral follicle count on ultrasound or ovarian volume measurement to identify perimenopause in people aged 45 and over (NICE NG23, 1.3.4). An FSH (follicle-stimulating hormone) test is only considered for people aged 40–45 with symptoms, or when menopause is suspected under age 40 (NICE NG23, 1.3.6).

In other words, the “test” for perimenopause is usually the story you tell and your cycle record.

If it isn’t perimenopause, what else could it be?

It is not right to put every change in your 40s down to perimenopause. If you use a hormonal method of contraception, it can be harder to notice the transition, because your periods are affected by that method (NHS, Symptoms; NICE NG23, 1.3.2). ACOG notes that changes in your periods are ordinary at this time but should still be reported to a clinician, because abnormal bleeding can be a sign of another problem (ACOG, FAQ047). The Turkish Ministry of Health also asks that irregular bleeding before and after menopause not be treated as ordinary (HSGM). For more detail on cycle changes, see irregular periods at 45.

What can you observe yourself?

The information that will help your clinician most is simple and can be recorded at home:

• The day each period starts, how many days it lasts and how heavy the bleeding is.
• The number of days between periods; differences of more than 7 days or gaps of more than 60 days.
• How many times a day hot flashes and night sweats come.
• How your sleep, mood and concentration are going.

The Menopause Society suggests tracking changes in bleeding in a calendar or a phone app and discussing them with a health professional (The Menopause Society, Perimenopause).

When should you see a doctor in perimenopause, and what should you ask?

The NHS suggests seeing your GP if you think your symptoms may be due to perimenopause and want to learn about your options. You should also see a doctor if you have palpitations, if your bleeding is getting heavier rather than lighter, or if you have bleeding after 12 months without a period (NHS, Symptoms).

At the appointment you could ask:

• Are my symptoms consistent with perimenopause, or do we need to look for another cause?
• Is a blood test meaningful at my age?
• Until when should I keep using contraception?
• My symptoms are affecting my daily life; what options are there, and what are their benefits and risks?

NICE recommends that the benefits and risks of each option be discussed with you (NICE NG23, 1.4.1). This page does not recommend any medication, supplement or treatment; talk through your options with your clinician.