Yes, hypervigilance can cause insomnia. When you have hypervigilance, you are in an increased state of arousal where you are jumpy, easily startled by sudden movements and noises, constantly scanning your surroundings for any signs of danger, and ready in an instant to fight or run from any danger you might encounter. So when you are this primed and vigilant, then your body is so juiced that you are too tense to fall asleep. Hypervigilance is often seen in PTSD (post traumatic stress disorder), and occurs after being exposed to a life-threatening trauma.