Why Am I Wide Awake at 3 AM? Perimenopause, Anxiety, Hormones, and Sleep Waking up at 3 AM and suddenly feeling wide awake? During perimenopause, changing hormones can affect sleep, anxiety, stress tolerance, and your ability to settle back down. And no, you're not necessarily doing anything wrong. In this article, Dr. Tera explores the connection between perimenopause, progesterone, cortisol, anxiety, and insomnia—and what you can actually do when your brain decides 3 AM is