Many women are unprepared for perimenopause because no one has explained what is happening biologically. This medical guide explains what perimenopause is, when it begins, typical symptoms, how long menopause lasts, and what research says about effective support.
Perimenopause & Menopause
Perimenopause catches many women unprepared. Not because of the symptoms themselves, but because no one has explained what is biologically happening. Poor sleep, which they blame on stress. Mood swings that feel like depression. Hot flashes that wake them up at night. And the feeling of no longer knowing their own body.
This is not a weakness. It is a hormonal transition that affects almost every organ system and is often not taken seriously enough in medical care. This medical guide explains what perimenopause is, when it begins, what typical symptoms are, how long menopause lasts, and what research says about effective support.
What is Perimenopause?
Perimenopause is the transitional phase before the last menstrual period, during which the ovaries gradually produce less estrogen and progesterone, and hormone levels fluctuate widely. For most women, it begins in their mid-40s, for some as early as their late 30s, and lasts an average of 4 to 7 years. During this time, the first typical symptoms appear: irregular cycles, hot flashes, sleep problems, and mood swings, often years before periods permanently stop. We explain the exact difference between perimenopause and menopause in more detail below.
What is Menopause? A Medical Classification
The term "menopause" is commonly used in everyday language, but in medicine, a more precise distinction is made. Climacteric refers to the entire transitional phase, from the first hormonal changes until several years after the last period. Menopause itself is just a single point in time: the day of the last menstruation, confirmed retrospectively if no bleeding has occurred for 12 months.
In Germany, the average age of the last period is 51, with a considerable range of 40 to 58 years. Around 1 percent of women experience premature menopause before the age of 40 (Premature Ovarian Insufficiency, POI), which should always be medically investigated.
The central mechanism: As women age, the ovaries produce less estrogen and progesterone. This decline is not a failure but a programmed physiological process. However, it has consequences for bones, the cardiovascular system, the brain, mucous membranes, and mood because estrogen receptors are distributed throughout the body.
What is the difference between perimenopause and menopause?
Perimenopause is the transitional phase before the last period. It can last 4 to 7 years and is characterized by irregular cycles, fluctuating hormone levels, and the onset of initial symptoms. Menopause is the date of the last period. Postmenopause begins afterward and can last for decades.
Important: Many symptoms that women describe as menopausal symptoms already occur during perimenopause, often years before the last period. Those who wait for their period to stop before seeking support wait too long. You can find more information in the article Perimenopause vs. Menopause: The Differences Explained Clearly.
When does menopause begin?
The first phase, perimenopause, begins for most women between 40 and 45 years old, and for some, as early as their late 30s. The first reliable indicator is changes in the menstrual cycle: shorter or longer intervals, heavier or lighter bleeding, or the first occurrence of spotting between periods.
| Phase | Period | Typical Signs |
|---|---|---|
| Premenopause | Reproductive phase, approx. 18 to 40 years | Estrogen regular and cyclical, normal cycle |
| Perimenopause | Approx. 4 to 7 years before the last period | Estrogen highly fluctuating with a decreasing trend, cycle irregularities, initial symptoms |
| Menopause | Time of the last bleeding | Estrogen significantly dropped |