What Is Perimenopause? Symptoms, Age of Onset and Duration

Published: 23 April 2026 · Medically reviewed by: Op. Dr. Murat Alpay

What is perimenopause (the transition to the menopause), at what age does it begin and how many years does it last? Perimenopause symptoms, when irregular periods need an examination, whether an FSH test is needed, and pregnancy and treatment options in this period.

The menopause does not happen in a single day. Before periods stop completely, there is a transition period in which hormones fluctuate and the pattern of periods changes; this is called perimenopause (the transition to the menopause). Many women do not know that complaints such as hot flushes, sleep problems or irregular periods are linked to this period. In this article we explain what perimenopause is, when it begins and how long it lasts, its symptoms and the treatment options. For the general picture of the menopause, see our what the menopause is page; for treatment, see our menopause treatment page.

What Is Perimenopause?

Perimenopause is a natural period that begins as the reproductive years draw to a close, comes with hormone fluctuations and irregular periods, and lasts until 12 months after the last period. If no period at all occurs for 12 months after the last period, the woman is considered to have reached the menopause.

In the international classification, the transition period is divided into two stages:

• Early transition: A persistent difference of 7 days or more begins to appear between the lengths of consecutive menstrual cycles. For example, a period that used to come every 28 days comes after 35 days one month and sooner another month.
• Late transition: Periods without menstruation lasting 60 days or longer occur. This stage usually covers the 1–3 years before the last period.

At What Age Does Perimenopause Begin, and How Long Does It Last?

• Onset: Perimenopause begins at an average age of 47–48.
• Duration: It lasts 1–4 years on average; from person to person it can stretch from 1 year to 10 years.
• Age of the menopause: The average age of natural menopause is 51; the general range is between the ages of 45 and 55.

Some factors that affect the age of the menopause are known:

• Linked to an earlier menopause: Smoking (brings the menopause forward by 1 year on average), exposure to smoking in the womb, low body weight, a first period at age 11 or earlier, menstrual cycles shorter than 25 days, ovarian surgery and chemotherapy (cancer treatment with medicines).
• Linked to a later menopause: Past use of the contraceptive pill, a high number of pregnancies and high body weight.

A menopause before the age of 45 is considered early menopause, and a menopause before the age of 40 is considered premature ovarian insufficiency. For details, see our article on early menopause.

Perimenopause Symptoms

Symptoms can begin before periods stop completely, in the early transition. The most common ones are:

• Hot flushes and night sweats: Seen in 70–80% of women in perimenopause. For details, see our hot flushes in the menopause page.
• Sleep problems: Waking at night and difficulty falling asleep become more frequent.
• Mood changes: Anxiety, irritability, outbursts of anger, emotional ups and downs and low mood may be seen.
• Brain fog: Forgetfulness, difficulty concentrating and mental cloudiness may become noticeable. For details, see our brain fog in the menopause page.
• Vaginal dryness: As the tissues become thinner, pain during sex and urinary complaints may begin. For details, see our vaginal dryness page.
• Muscle and joint pain: Joint stiffness and pain may increase in this period.

For the full range of complaints that come with the menopause, see our article on menopause symptoms.

Irregular Periods in Perimenopause: What Is Normal and What Is Not?

Because ovulation becomes less frequent, it is expected in this period for periods to become shorter or longer, for spotting to appear in between, and for bleeding to be lighter or heavier than usual.

However, the following types of bleeding should not be put down to perimenopause and brushed aside; they require an examination:

• Very heavy bleeding: Bleeding with clots, heavy enough to soak a large pad or tampon every 1–2 hours
• Prolonged bleeding: Bleeding that lasts longer than 7 days
• Frequent or continuous bleeding: Bleeding that comes at intervals shorter than 21 days or continues almost every day
• Bleeding between periods and bleeding after sex: Spotting between two periods, or bleeding after sex

In these situations a pregnancy test, a thyroid test and a vaginal ultrasound are done; if needed, a sample is taken from inside the womb, or the inside of the womb is examined with a camera (hysteroscopy), to look for causes in the lining of the womb such as a polyp, a fibroid or thickening. For period problems, see our irregular periods page.

Diagnosing Perimenopause: Is an FSH Test Needed?

The diagnosis of perimenopause is usually made on the basis of age, the change in the pattern of periods and the symptoms.

• Over the age of 45: An FSH or AMH blood test is not needed and is not recommended. Because hormone levels fluctuate a great deal in this period, a normal FSH result can be misleading.
• Between the ages of 40 and 45: In women with irregular periods, an FSH test may be requested to help with the diagnosis while ruling out pregnancy and disorders of the thyroid and of the milk hormone (prolactin).
• Before the age of 40: In women whose periods become irregular or stop, a blood test is needed. For the diagnosis, a raised FSH level is looked for in two tests taken 4–6 weeks apart.

The AMH test shows the ovarian reserve (the number of eggs remaining); it is not the first-choice test for diagnosing the menopause.

Can You Get Pregnant During Perimenopause?

Yes. Although ovulation becomes less frequent, the possibility of pregnancy continues. For this reason, if pregnancy is not wanted, contraception should be continued:

• In women whose last period is before the age of 50: Contraception is recommended for at least 2 years after the last period.
• In women whose last period is after the age of 50: Contraception is recommended for at least 1 year after the last period.
• At the age of 55, contraception can be stopped, because the possibility of natural pregnancy no longer remains.

Combined contraceptive methods containing oestrogen are stopped at the age of 50 at the latest, because of the risk to the heart and blood vessels.

Treatment Options in Perimenopause

Treatment is planned together with the doctor according to the severity of the complaints, the woman's medical history and her preference:

• Hormone therapy: In women whose periods have not yet ended and who have a womb, a cyclical regimen is preferred in which progesterone is added to oestrogen on certain days of the month; this way a light withdrawal bleed occurs every month. Continuous combined therapy is not given to a woman whose periods have not ended, because it leads to irregular bleeding. For hormones with the same structure as those the body produces, see our bioidentical hormone therapy page.
• Options that provide both contraception and treatment: The hormone-releasing intrauterine device (coil) protects against pregnancy, reduces heavy bleeding and protects the lining of the womb during hormone therapy. Low-dose contraceptive pills can also be used before the age of 50, in women who do not smoke and have a low risk of blood clots, for contraception, for bleeding control and to reduce hot flushes.
• Non-hormonal options: In women who cannot use or do not want hormone therapy, cognitive behavioural therapy (a talking therapy aimed at changing habits of thought and behaviour) and some non-hormonal medicines may be options.
• Lifestyle: A Mediterranean-style diet, regular walking and resistance exercise, stopping smoking, cutting down on caffeine and alcohol, and regular sleep habits are recommended.

On when to start hormone therapy, see our article when to start hormone therapy in the menopause.

Frequently Asked Questions

What is the difference between perimenopause and the menopause?

Perimenopause is the transition period in which periods begin to become irregular. The menopause, on the other hand, is the diagnosis made once 12 months have passed since the last period.

Can there be symptoms in perimenopause before periods stop?

Yes. Hot flushes, sleep problems and mood changes can begin in the early transition, before periods have stopped.

Can a blood test tell me whether I have reached the menopause?

After the age of 45 a blood test is usually not needed and can be misleading; the diagnosis is made according to the pattern of periods and the symptoms. If there is a change in the pattern of periods before the age of 45, a blood test may be needed.

My period has not come for 2 months during perimenopause. Could I be pregnant?

You could. Because the possibility of pregnancy continues in this period, a pregnancy test should be done first when a period is late.