4 phases of menopause: How your body changes

From the beginning of your 40s, you probably start to feel your body slowly changing: your cycle becomes irregular, the nights shorter, your mood fluctuates, and often you're left wondering what's happening and whether menopause has already begun.

Menopause is a natural but complex phase in every woman's life. It spans several years and is accompanied by various hormonal and physical changes. This article provides you with sound, easy-to-understand guidance so you know where you stand and how you can consciously navigate this phase of life.

The most important points in brief

• The menopause comprises four phases: premenopause, perimenopause, menopause, and postmenopause.
• The average age for menopause is 50 years.
  
• Perimenopause is the phase with the most symptoms and the strongest hormonal fluctuations.
  
• The entire transition phase lasts on average about 4 years, but can vary greatly from person to person.

An overview of the 4 phases of menopause

Menopause is not a single phase, but a gradual process that extends over several years. Scientifically, researchers distinguish four main phases, which can be defined by the STRAW+10 system (Stages of Reproductive Aging Workshop). This system is based on numerous studies and helps to categorize hormonal and physical changes (1).

1. Premenopause : First hormonal changes from mid-30s/early 40s. The number of available eggs in the ovaries slowly decreases, but the cycle usually remains regular.
2. Perimenopause : The transition phase with the strongest symptoms. It begins with irregular cycles (usually from the mid-40s) and only ends 12 months after the very last period.
3. Menopause : The point at which the last menstrual period occurs. It is only determined retrospectively after 12 months without a period. The average age is 50.
   
4. Postmenopause : The phase after menopause that lasts for the rest of one's life. It begins once a full year has passed since the last menstrual period (2).

The transitions between the phases are fluid. Every woman experiences them differently, both in duration and in the intensity of the symptoms.

Phase 1 – Premenopause: First hormonal changes

What is perimenopause?

The perimenopause marks the beginning of hormonal changes, even if these are often not yet noticeable. It is the late reproductive phase in a woman's life, before pronounced menopausal symptoms appear.

Age : Typically from early/mid-30s to mid-40s, sometimes even earlier
Duration : Highly variable, often several years

What happens in the body?

During this phase, the number of available eggs (ovarian reserve) naturally begins to decline. Hormones such as anti-Müllerian hormone (AMH) and inhibin B, produced by the ovarian follicles, decrease. In response, follicle-stimulating hormone (FSH) may temporarily increase. The body is essentially trying to compensate for the declining ovarian function (1).

Typical characteristics

The menstrual cycle can change slightly, becoming somewhat shorter or longer. Initial, mild symptoms are possible: slight mood swings, occasional sleep problems, or minimal cycle variations. However, many women experience no symptoms at this stage (3).

Good to know: This phase often goes unnoticed. Many women only become aware of significant changes during perimenopause. Pregnancy is still possible during perimenopause, even though fertility gradually declines. The hormonal adjustments are still subtle and fluctuate from cycle to cycle.

Phase 2 – Perimenopause: The most intense phase

Perimenopause is the phase with the most and most intense symptoms and often presents a major challenge for many women. It is also referred to as the "menopausal transition" and marks the actual transition period to menopause.

What is perimenopause?

The transition phase, which begins with irregular menstrual cycles and ends 12 months after the last period, is called perimenopause. Perimenopause can be divided into two subphases: Early perimenopause begins when the cycle interval varies by at least 7 days. Late perimenopause is characterized by longer intervals of at least 60 days between periods.

Age : Usually between 45 and 50 years, but can also begin earlier or later.
Duration : On average about 4 years, but for some women it can last 7 years or longer.

What happens in the body?

During perimenopause, sex hormone levels fluctuate dramatically. Estrogen levels can unexpectedly rise and then plummet. These extreme fluctuations are characteristic of this phase. FSH levels continue to rise as ovarian reserve diminishes. Menstruation becomes increasingly irregular: the intervals between periods lengthen, and the flow varies from very heavy to very light. Ovulation occurs less frequently and sometimes ceases altogether.

Perimenopause is the most challenging phase, but it is temporary! However, those who experience symptoms earlier in perimenopause often experience them for a longer period.

Typical symptoms of perimenopause

• Hot flashes and night sweats are the most common symptoms. Approximately 80% of menopausal women experience these so-called vasomotor symptoms. Hot flashes typically last a few minutes and begin with a sensation of heat spreading across the upper body, accompanied by skin reddening and sweating.
  
• Mood swings, anxiety, and depressive moods also become more common. Women in perimenopause have an increased risk of depressive symptoms. The hormonal fluctuations affect neurotransmitters such as serotonin, dopamine, and norepinephrine, which are important for mood regulation.
• Sleep problems affect as many as 40% of women in perimenopause. The most common symptom is waking up during the night. Changes in estrogen and FSH levels correlate with difficulty falling asleep and staying asleep.
  
• Dry skin and mucous membranes result from declining estrogen levels. The mucous membranes in the vaginal area are particularly affected (4).
  

Phase 3 – Menopause: The time of the last period

What is menopause?

The point in time when a woman has her last menstrual period. Menopause marks the end of a woman's reproductive life. It occurs when the ovaries have permanently ceased to function.

Age : On average around 50 years (varies individually)

How is it determined?

Menopause can only be confirmed retrospectively after 12 consecutive months without a period. This means you won't know for sure that your last period was until a year later. This waiting period is important because longer intervals between periods can occur in late perimenopause.

A blood test to measure FSH levels is possible, but not absolutely necessary. Elevated FSH levels in combination with absent menstruation can be an indicator, but hormone levels fluctuate considerably during perimenopause.

What happens in the body?

The ovaries largely cease production of female sex hormones. Estrogen levels drop to a permanently low level. Follicle maturation and therefore ovulation no longer occur. Pregnancy is no longer possible from this point onward.

Good to know: Contraception can only be discontinued after 12 months without a period. Before that, there is still a theoretically minimal chance of pregnancy.

Phase 4 – Postmenopause: New equilibrium

What is postmenopause?

The phase after the last menstrual period for the rest of one's life. Postmenopause is divided into an early phase (the first few years after menopause) and a late phase (the years thereafter).

Start : From 12 months after the last period
Duration : The rest of your life

What happens in the body?

Hormone levels stabilize at a new, permanently lower level. Estrogen deficiency is now stable, and there are no longer the large fluctuations seen during perimenopause. The body has found a new hormonal balance and is adapting to these changes.

Symptoms in postmenopause

Many acute symptoms, such as hot flashes and mood swings, gradually subside in the early postmenopause. The hormonal rollercoaster of perimenopause is over, which many women find to be a great relief.

However, long-term effects of persistent estrogen deficiency are becoming apparent:

• The risk of osteoporosis increases significantly: Estrogen is essential for bone metabolism. It promotes bone-building cells, called osteoblasts, and regulates bone-resorbing cells, called osteoclasts. Estrogen deficiency leads to accelerated bone loss. Bone density decreases rapidly, particularly in the three years surrounding menopause, and continues to decline thereafter (5).
  
• Vaginal dryness and urogenital discomfort: The declining estrogen level leads to changes in the vaginal mucosa. Blood flow decreases, vaginal lubrication diminishes, the pH level rises, and the tissue becomes thinner. These changes can not only affect the intimate area but also impair sexual function and increase the risk of urinary tract infections (4).
  
• Weight gain and body composition: Metabolism changes with age, which is normal. However, hormonal changes during menopause significantly accelerate this process. Basal metabolic rate can decrease by up to 250–300 calories per day, muscle mass declines more rapidly, and fat tissue accumulates more in the abdominal area, the so-called “visceral fat.” This abdominal fat is particularly problematic because it promotes inflammatory processes in the body and increases the risk of cardiovascular disease (6).
• Cardiovascular changes are an important, often overlooked aspect of menopause. Earlier age at natural menopause is associated with an increased risk of cardiovascular disease (7).

In summary, many women feel more stable and balanced in postmenopause. The body has found a new equilibrium . Without menstruation and without the strong hormonal fluctuations, many women experience this phase as liberating. They can plan their lives without having to think about cycles or menstrual discomfort. After the early postmenopause, around the mid-60s, the term "menopause" is no longer actively used, as the body has fully adapted to the hormonal changes.

Important : Postmenopause is not a time of deprivation or restrictions. It's a time when you can actively shape how you want to age. With the right steps, you can experience this phase of life with energy and health. Right now, targeted measures can make a big difference in staying fit and vital in the long term. Learn more here .

How do I know which phase I'm in?

You are probably in perimenopause if:
• You are between your mid-30s and mid-40s
• Your cycle is still largely regular
• You may notice mild mood swings or occasional sleep problems
• But you don't yet have any significant menopausal symptoms

You are probably in perimenopause if:
• You are between 45 and 50 years old (but this can vary)
• Your menstrual cycles become irregular – longer or shorter intervals, varying bleeding intensity
• You experience hot flashes, night sweats, or strong mood swings
• You have sleep problems and difficulty concentrating
• Your symptoms fluctuate greatly – sometimes better, sometimes worse

You have reached menopause when:
• 12 months have passed since your last period
• You are around 50 years old (or earlier/later – it varies from person to person)

You are postmenopausal if:
• More than 12 months have passed since your last menstrual period
• Acute symptoms such as hot flashes gradually subside
• You feel a new hormonal stability
• You are over 50 years old

Note : This classification is a guideline. If you are unsure or experiencing severe symptoms, a consultation with your gynecologist can help. Hormone tests are possible, but not always conclusive, as levels can fluctuate significantly depending on the phase of your cycle.

Individual differences: Why every woman experiences menopause differently

Women experience the onset, duration, and intensity of symptoms very differently. This variability is not random, but rather the result of a complex interplay of various factors.

Factors that influence how you experience menopause:

• Genetic predisposition : The age at which your mother or sisters experienced menopause provides an important clue about your own timing. The genetic component is one of the strongest predictors of the timing of menopause.
  
• Lifestyle and health behaviors : Dietary habits, regular physical activity, and personal stress levels have a measurable impact on symptom intensity. A healthy lifestyle has been shown to alleviate symptoms (6).
  
• Ethnic origin: Large-scale studies demonstrate significant differences between ethnic groups. For example, African American women often experience longer and more intense hot flashes than women of other ethnicities (4).
  
• Physical constitution : Body mass index (BMI) and body composition influence both hormone metabolism and symptom perception. Body fat can store estrogen precursors, which affects the hormonal balance.
  
• Nicotine consumption : Smoking has been shown to accelerate the onset of menopause. Smokers tend to experience their last period earlier and more frequently report more intense vasomotor symptoms (1).

Conclusion

Menopause is a long-term process with four distinct phases. From the initial hormonal changes in premenopause, through the symptom-rich perimenopause, to the newfound stability in postmenopause. Each phase brings its own challenges and changes.

Understanding which phase you're in can help you put the changes into perspective and seek support in a timely manner if necessary. Whether through lifestyle adjustments, targeted nutritional supplements, or medical guidance – you have options to actively and healthily navigate this phase of your life.

Frequently Asked Questions

1. How can I tell if I'm at the beginning of menopause?
   Early signs can include slight changes in the menstrual cycle, sleep problems, or mood swings. In this early phase (perimenopause), the changes are often still subtle.
2. What is the difference between premenopause and perimenopause?
   Premenopause describes the first hormonal changes, usually while the menstrual cycle is still regular. Perimenopause is the transition phase with irregular cycles and the most severe symptoms.
3. At what age do menopause and menopause usually begin?
   The first hormonal changes can begin as early as the mid-30s. Perimenopause often starts between 45 and 50 years of age, and menopause occurs on average at 50 years of age.
4. How long does menopause last in total?
   The duration varies greatly from person to person. The actual transition phase (perimenopause) lasts on average about four years, but can also be seven years or longer.
5. Why are the symptoms in perimenopause often so severe?
   During this phase, hormone levels fluctuate significantly. Estrogen, in particular, rises and falls unpredictably, which can contribute to symptoms such as hot flashes, sleep disturbances, and mood swings.
6. When is menopause medically defined?
   Menopause is reached when twelve months have passed since the last menstrual period. Only then can it be reliably determined in retrospect.
7. Do menopausal symptoms subside after menopause?
   Many women experience a decrease in acute symptoms such as hot flashes after menopause. However, long-term changes, for example to the bones or cardiovascular system, remain significant.
8. Can I still get pregnant despite having an irregular cycle?
   Yes. Pregnancy is still possible during the pre- and perimenopause, even though fertility declines. Contraception therefore remains important.
9. How can I find out what stage of menopause I am in?
   Age, menstrual cycle changes, and typical symptoms provide initial clues. A gynecological consultation can help to better understand the phase of your cycle.
10. Are menopause and menopause the same for every woman?
    No. The timing, duration, and severity of symptoms are influenced by factors including genetics, lifestyle, body composition, and stress. Every woman experiences this phase differently.

literature
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2. Stute P. Management of Menopause. Berlin, Heidelberg: Springer Berlin Heidelberg; 2025.
3. Vikram Talaulikar. Menopause transition: Physiology and symptoms. Best Practice & Research Clinical Obstetrics & Gynecology 2022; 81:3–7. Available at: https://www.sciencedirect.com/science/article/pii/S1521693422000426.
4. Delamater L, Santoro N. Management of the perimenopause. Clin Obstet Gynecol 2018; 61(3):419–32. doi: 10.1097/GRF.0000000000000389.
5. Yang JL, Hodara E, Sriprasert I, Shoupe D, Stanczyk FZ. Estrogen deficiency in the menopause and the role of hormone therapy: integrating the findings of basic science research with clinical trials. menopause 2024; 31(10):926–39. doi: 10.1097/GME.0000000000002407.
6. Erdélyi A, Pálfi E, Tűű L, Nas K, Szűcs Z, Török M et al. The Importance of Nutrition in Menopause and Perimenopause-A Review. Nutrients 2023; 16(1). doi: 10.3390/nu16010027.
7. El Khoudary SR, Aggarwal B, Beckie TM, Hodis HN, Johnson AE, Langer RD et al. Menopause Transition and Cardiovascular Disease Risk: Implications for Timing of Early Prevention: A Scientific Statement From the American Heart Association. Circulation 2020; 142(25):e506-e532. doi: 10.1161/CIR.0000000000000912.