Stress and our body's response to it are a natural and inevitable part of life. Humans inherited this stress response through years of harsh environments and physical threats to our ancestors. Though often shortened to "fight or flight," the more response is actually more like "fight, flight, freeze or faint." This response relies on a system called the hypothalamic-pituitary-adrenal axis, or HPA, which function to maintain physiological homeostasis.

The HPA regulates metabolism, immune responses, and the autonomic nervous system, and it begins to develop as early as the fetal stage! Challenges in the maternal environment can also create dysfunction in the fetal HPA development. The system is complex, releasing multiple hormones which regulate each other while regulating body processes.

Epinephrine, often referred to as adrienaline, is one of those hormones. This chemical messenger helps transmit nerve signals across nerve endings to dilate pupils, divert blood away from skin and to your muscles, encourage your heart to pump harder and faster, convert glycogen to glucose from your liver, and breathe deeper, delivering more oxygen to your blood.

While acute stress may spur on these positive changes, chronic stress can actually be immunosuppressive and damaging. Experts think that mindfulness, including amindful journaling practice, could help manage the difficulties that come with chronic stress. For more on mindfulness approaches and interventions, the work of David Creswell is compiled here.