If you are a woman in your 40s who has spent decades being the one who holds it all together — the high performer, the fixer, the person everyone leans on — you may have noticed something lately that you can't quite name. The same stressors you used to absorb without a second thought now leave you wired, depleted, and staring at the ceiling at 3 a.m. You are doing everything you used to do, but the buffer that made it feel effortless seems to have quietly disappeared. You are not imagining it, and you are not failing.

Yesterday, a patient in her early forties sat across from me describing something she had never experienced before: her heart would suddenly race for no apparent reason, jolting her awake at 2 a.m. She could not fall back asleep. She felt foggy at work. She wondered if something was seriously wrong. Nothing was wrong with her heart. What she was experiencing were some of the earliest signals of perimenopause. The purpose of this blog is to walk you through the major body systems affected by perimenopause and to show you what to expect at each phase. My hope is that by understanding these changes, you will feel empowered rather than frightened, and that you will recognize the signals your body is sending you as it moves through this natural, but sometimes disorienting, transition.