adrenaline is a hormone that is produced by the adrenal glands when a person faces a stressful, dangerous, or exciting situation. It triggers the fight-or-flight response, which prepares the body to either confront or escape the threat. adrenaline increases heart rate, blood pressure, breathing rate, blood sugar, and alertness. It also reduces pain perception and dilates the pupils. adrenaline can help a person survive or perform better in challenging circumstances, but too much or too little adrenaline can cause health problems.
