Just before we're about to go out onstage, a great surge of energy rushes through us all and gives us a sense of invincibility. This is called an adrenaline rush. Adrenaline rushes are common before performances, games, or near death experiences. Adrenaline, also known as Epinephrine, is a hormone and neurotransmitter. It causes increase in heart rate, contracts blood vessels, dilates air passages, and triggers the flight-or-fight response. Adrenaline is produces by the adrenal gland, specifically from the amino acids phenylalanine and tyrosine.