Catecholamines are a group of hormones produced by the adrenal glands, primarily in response to stress. The main catecholamines include epinephrine, norepinephrine, and dopamine. These hormones play a crucial role in the body's "fight or flight" response, helping to prepare the body for quick action by increasing heart rate, blood pressure, and energy availability. Catecholamines are also involved in regulating various physiological functions, such as mood, attention, and metabolism. They act as neurotransmitters in the brain, influencing emotional responses and cognitive functions. Imbalances in catecholamine levels can be associated with conditions like depression, anxiety, and ADHD.