What is perimenopause?

Perimenopause is the transitional period before menopause — the years during which the ovaries gradually produce less oestrogen and the menstrual cycle becomes irregular before stopping entirely. The word means "around menopause," and it's the phase most people are actually living through when they talk about "going through menopause."

Menopause itself is a single point in time: 12 consecutive months without a menstrual period. Everything before that point, while symptoms are active and cycles are changing, is perimenopause.

When it starts

Perimenopause typically begins in the mid-40s, but it can start as early as the late 30s. The average duration is 4–8 years, though it can be shorter or considerably longer. Because early symptoms — irregular periods, sleep changes, mood shifts, increased anxiety — overlap with stress, burnout, and other conditions, perimenopause is frequently not recognised for what it is.

There's no blood test that definitively confirms perimenopause. FSH and oestrogen levels fluctuate significantly during this period, so a single measurement is unreliable. Diagnosis is primarily clinical — based on age, symptoms, and menstrual pattern changes.

What's happening hormonally

Oestrogen doesn't decline in a smooth, linear way during perimenopause. It fluctuates — sometimes spiking higher than premenopausal levels before dropping. This unpredictability is one of the reasons symptoms can be so variable: it's not simply a matter of "low oestrogen" but of erratic oestrogen that the body is struggling to adapt to.

Progesterone typically starts declining first, which can cause irregular cycles, heavier periods, and changes in PMS symptoms even before oestrogen drops significantly.

Common symptoms

Perimenopause symptoms vary widely between individuals. The most commonly reported include hot flashes, night sweats, sleep disruption, mood changes (irritability, anxiety, low mood), brain fog, irregular periods, joint pain, and changes in libido. Not everyone experiences all of these — some people have minimal symptoms, others find this period significantly disruptive to daily life.

The variability is one reason tracking is useful. Symptoms that appear random often show patterns when logged consistently — correlating with sleep quality, stress levels, cycle phase, or specific triggers.