Perimenopause is one of the most biologically complex, and socially overlooked, stages of a woman’s life. It is not a single moment or diagnosis but a hormonal transition that unfolds over years as ovarian function gradually changes. During this time, levels of estrogen and progesterone fluctuate unpredictably, affecting the brain, nervous system, metabolism, sleep, joints, and mood. The result is a wide constellation of symptoms that many women experience long before menopause is ever discussed.
Clinically, perimenopause refers to the menopausal transition leading up to menopause, which is defined as twelve consecutive months without a menstrual period. A major clinical review published in The BMJ reports that menopause occurs at a median age of 51, and that perimenopause typically begins several years earlier — most often between ages 45 and 55 — with an average duration of about seven years. Importantly, symptoms can begin even earlier, sometimes in a woman’s late 30s or early 40s.
What makes the symptoms of perimenopause especially challenging is not only how common they are, but how often they are misunderstood. Many women experience multiple symptoms at the same time, yet are told they are simply stressed, aging, anxious, or burned out. Research consistently shows that perimenopausal symptoms are biologically driven and highly prevalent — but gaps in education and awareness mean they are frequently missed or misattributed.
Hormonal fluctuations during perimenopause have a direct effect on the brain, which helps explain why neurological and psychological symptoms are so common. Estrogen plays a key role in regulating neurotransmitters such as serotonin, dopamine, and GABA, all of which influence mood, anxiety, cognition, and sleep. As hormone levels rise and fall unpredictably, many women experience irritability, anxiety, low mood, or emotional volatility. Clinical guidance from The BMJ emphasizes that these mood changes are a core feature of the menopausal transition, not simply reactions to life circumstances.
Sleep disturbance is another hallmark symptom of perimenopause and one of the most widely reported. A narrative review in the Journal of Clinical Medicine found that approximately 70% to 90% of women experience sleep problems during the menopausal transition, including insomnia, frequent awakenings, and non-restorative sleep. These disruptions occur even in women with no prior history of sleep disorders and are closely linked to hormonal effects on circadian rhythm and thermoregulation.
Fatigue often follows closely behind. Large surveys indicate that persistent physical and mental exhaustion affects roughly three-quarters or more of women during perimenopause. An international analysis summarized by The Menopause Society identified fatigue and exhaustion as among the most commonly reported symptoms across countries and cultures . This fatigue is rarely resolved by rest alone, as it is driven by a combination of sleep loss, hormonal shifts, and increased stress sensitivity.
While hot flashes are the most widely recognized symptom of perimenopause, they are only one part of a broader physiological picture. Vasomotor symptoms — including hot flashes and night sweats — occur when fluctuating estrogen disrupts the brain’s temperature regulation. A large global meta-analysis published in BMC Public Health, which analyzed data from more than 480,000 women, confirmed that vasomotor symptoms affect approximately 50% to 80% of women during the menopausal transition. Night sweats, in particular, contribute significantly to sleep disruption and downstream symptoms such as fatigue and cognitive impairment.
One of the most underrecognized yet highly prevalent symptoms of perimenopause is joint and muscle pain. Estrogen has anti-inflammatory effects and supports connective tissue health, and its fluctuation can lead to stiffness, aches, and generalized discomfort. The same BMC Public Health meta-analysis found joint and muscle pain to be the most commonly reported symptom overall, affecting approximately 65% of women — more than hot flashes in many populations.
Cognitive symptoms, often described as “brain fog,” are also frequently reported during perimenopause. Women may notice forgetfulness, difficulty concentrating, slower processing speed, or word-finding challenges. Although these symptoms are less consistently quantified than physical complaints, clinical reviews note that they are closely associated with hormonal changes and sleep disruption and are typically temporary. The BMJ review highlights cognitive changes as a recognized feature of the menopausal transition rather than a sign of permanent decline.
Changes in menstrual cycles are a defining feature of perimenopause and often the earliest visible sign that the transition has begun. Periods may become irregular, heavier, lighter, or unpredictable as ovulation becomes inconsistent. By definition, nearly all women in perimenopause experience some form of menstrual change, yet these changes are often discussed without broader context around hormonal health.
Sexual and urogenital symptoms can also emerge during perimenopause. Declining and fluctuating estrogen levels affect vaginal tissue elasticity, lubrication, and blood flow, contributing to vaginal dryness, discomfort, and changes in sexual desire. Systematic reviews estimate that between 20% and 60% of women experience low libido or vaginal symptoms during the menopausal transition, though these symptoms are frequently underreported and undertreated.
Despite how common these symptoms are, perimenopause is still rarely identified early. Many women spend years seeking answers while their symptoms are treated in isolation rather than recognized as part of a broader hormonal transition. Clinical experts increasingly emphasize that earlier recognition of perimenopause can improve care, reduce unnecessary testing, and validate women’s lived experiences.
Understanding the symptoms of perimenopause is not about medicalizing a natural stage of life — it’s about restoring clarity, agency, and informed choice. When women understand why symptoms occur and how common they truly are, they are better equipped to advocate for themselves and seek appropriate support.
This is where tracking matters. Patterns over time, not isolated symptoms, are often what reveal perimenopause. Having a clear, private record of your sleep, mood, cycles, energy, and physical symptoms can make conversations with healthcare providers more productive and empowering.
The Pause app was built for exactly this moment. We are a female-founded platform designed to help women track perimenopause symptoms, understand what’s happening in their bodies, and feel less alone during this transition. Your data belongs to you — we do not sell your data, ever. Privacy, trust, and evidence-based insight are foundational to everything we build.
If you’re experiencing symptoms of perimenopause or simply want clarity about your health, download The Pause App and start tracking what matters — with confidence, privacy, and support.
Written by: Susan Sly – Founder & CEO of The Pause Technologies, Inc.