What causes dilated pupils and racing pulse?

Adrenaline surge... Adrenaline is the principal mediator of the "fight or flight" response. This prepares your body for immediate action. Pupils dilate to increase light transmission, heart rate and blood pressure go up and blood is shunted away from other organs to the skeletal muscles. If this occurring in the absence of a stimulus, it is likely due to hypoglycemia or low blood sugar. Check for Insulin resistance.