Perimenopause in one sentence
Perimenopause is the transition that comes before menopause. That is the plain definition. For what it means in your own body and on what timeline, a licensed clinician is the right person to ask.
How to read up without losing a week

You do not need to read everything. Pick two or three public sources and read them once. The FDA's menopause page, the Office on Women's Health menopause page, and the Menopause Society's patient page on sexual health are a reasonable set to start from.
As you read, write down terms you do not recognize and anything that sounds like your own experience. Bring that page to your appointment. It turns a long reading session into five good questions.
From reading list to appointment
- Read your chosen sources once and mark what stands out.
- Start a short dated note of changes you notice.
- Book a visit and bring your questions.
- Ask what follow-up looks like and what to track in between.
Who can answer for you
Reading and note-taking get you ready for the appointment, but a licensed clinician is the one who can tell you where you are in the transition.