Adrenaline — The Instant Wake-Up Chemical

Adrenaline (also called epinephrine) is a fast-acting hormone and neurotransmitter released during stress. When your brain senses a threat — a real one or just an anxious thought — nerves tell the adrenal glands to flood your system with adrenaline. Heart rate jumps, breathing speeds up, muscles tense, pupils widen, and blood is shunted toward “fight or flight” systems.

That’s perfect if you need to slam the brakes, dodge a bike, or deliver an emergency presentation. It’s the opposite of what you want at 1 a.m. in bed. Because adrenaline’s whole job is to keep you alert and ready, it directly clashes with the slow, parasympathetic, wind‑down physiology that supports sleep.

Adrenaline spikes can be triggered by obvious stressors — arguments, deadlines, scary news — but also by internal loops: worrying about not sleeping, replaying conversations, doomscrolling. Your brain doesn’t distinguish much between a tiger and a catastrophic thought; if it feels threatening, the body responds.

You can’t veto adrenaline, but you can influence how often and how long it surges. Soothing routines, breathing that lengthens the exhale, limiting high‑arousal content before bed, and addressing underlying anxiety (with therapy, CBT‑I, or medication when needed) all help signal that your system doesn’t need full sirens at night.

Why It Matters

Understanding adrenaline turns “my body betrays me at night” into “my alarm system is overreacting” — something you can work with, not just endure.

Closing Line

Adrenaline is brilliant at keeping you alive; your job at bedtime is gently proving that, for the next few hours, survival does not require a full-body fire drill.