To a woman of forty, the word perimenopause belongs to someone else. It belongs to her mother, to an older friend, or to some distant version of herself she has no reason yet to think about, but certainly not to her. She is too young for that—still building her life: raising children, managing a career, caring for everyone around her. She is strong. She is vital. Menopause, in her mind, is a chapter that begins somewhere in her fifties, and the years leading up to it haven’t entered her mind.
So when I suggest that perimenopause may be part of what she is experiencing, the response is almost always the same. A look of genuine disbelief, sometimes a startled laugh, and then: “I’m only forty. Why are you talking to me about perimenopause?”
In The Fifth Decade, I explain that women in their late thirties may already be experiencing the subtle beginnings of this transition, and that “these women are not remotely thinking about being near perimenopause or menopause. They would probably consider you crazy if you tried to make such a suggestion.” Many years of research and clinical work have confirmed that observation.
Our forty-year-old woman’s disbelief is entirely understandable. Almost no one has told her otherwise. What is missing from her understanding is the long transition that comes before menopause. And it is in that transition, not in menopause itself, that many women first find their patience shorter, their moods less predictable, and their sense of themselves quietly shifting, without any framework for why.
So when I raise perimenopause with a woman of forty, I am not suggesting she is old. I am suggesting she may be in a process no one told her would begin so young.
The Quiet Arithmetic of the Transition
Menopause itself is a single point in time, defined as twelve consecutive months without a menstrual period. Natural menopause typically arrives somewhere between the ages of forty and fifty-eight, with an average age of fifty-one.
Perimenopause is what comes before that point: the transition between the fertile years and menopause, sometimes called the climacteric. As I describe in The Fifth Decade, it can last from two to ten years before menstruation stops entirely. It typically begins in a woman’s forties, but it may begin as early as the late thirties.
It is worth remembering how recent this understanding is. It was not until 2001 that perimenopause was officially defined as a distinct phenomenon, separate from menopause. Many women in their forties today grew up with no language for it at all.
The arithmetic is simple, and it is rarely spelled out. If menopause arrives, on average, around fifty-one, and the transition leading to it can span a decade, then forty is not a premature age to be thinking about perimenopause. For many women, it is the age at which the transition has already quietly begun.
What makes this early phase so disorienting is its pattern. For generations it was assumed that perimenopause was simply puberty in reverse, a steady decline in estrogen. The research tells a different story. Early in perimenopause, estrogen levels actually rise, at times exceeding the levels of a woman’s younger years, while progesterone, which tempers and balances estrogen’s effects, begins to fall short. The result is not a gentle dimming but an imbalance, and the brain, exquisitely sensitive to these hormones, feels it.
The First Stage: Before There Are Words for It
In The Fifth Decade, I describe perimenopause as unfolding in four psychological stages. The first, which I call Perimenopausal Initiation, is the one women most often miss, because it rarely announces itself through the body.
In this stage, a woman typically notices no change in her menstrual cycle. She has no hot flashes and no night sweats. What changes first is something harder to measure: her mood and her degree of patience. Her threshold for tolerating unpleasantness or distress is slightly lower. As I wrote in the book, “Their reactivity is a bit quicker and slightly more intense than ever before.” She is brought to tears a bit more easily. She snaps at a lesser offense.
Women in this stage often describe a sense of feeling saturated, of having simply had enough: of the clothes left on the floor, the homework that needs reminding, the dishes that never quite make it into the dishwasher. Because those frustrations are real, it is entirely natural to locate the cause there. But, as I wrote, “The difference between ordinary frustration and the feelings of the women in Perimenopausal Initiation is primarily a matter of intensity and the ability to cope.”
Sometimes it is a family member who notices first. A child asks, “Mom, why do you look so mad?” She is surprised, denies being angry, and yet cannot shake an emotional discomfort she has no way to explain. That moment of perplexity, the sense that something has shifted without any language for it, is the signature of this stage.
The question in the subtitle of my book, Is It Just My Life or Is It Perimenopause?, is the question of this stage.
For many women, the answer begins with recognizing that perimenopause may be part of the picture long before the physical signs they have been taught to expect appear.
