Why You Wake Up at 3am with Anxiety: The Cortisol Awakening Response

Clock showing 3am with dark room representing cortisol awakening response and anxiety at night

Waking at 3am with racing heart and dread is triggered by the cortisol awakening response (CAR), which peaks at 30-45 minutes after waking and is amplified by chronic stress and HPA dysregulation. Here is the mechanism and what works.