Our acute stress response system, also known as the fight-or-flight response, was developed 40,000 years ago as a survival mechanism. It was designed for short bouts of stress, like when our ancestors were being pursued by a sabre toothed tiger and needed the extra energy & power to fight or flee.
When we are in a stressful situation and the brain perceives our life is under threat, like stumbling across a Sabre tooth tiger, a series of reactions occur in the body at lightning speed. The amygdala (fear center) in the brain sends a distress signal to the hypothalamus (master controller) to activate the sympathetic nervous system. A signal is then sent via the nerves to the adrenal glands, triggering them to produce adrenalin. This sudden surge of adrenalin causes our blood vessels to constrict thereby increasing our heart rate & blood pressure, and redistributes blood to our muscles & brain, in order to make us stronger and more alert. Once this initial surge of adrenalin starts to dissipate, the Hypothalamus-Pituitary-Adrenal-Axis (HPA-Axis) takes over. The Hypothalamus sends hormone messengers to the pituitary gland, which then sends a message to the adrenal glands to produce the hormone cortisol. Cortisol raises blook glucose in our blood to give us the energy to fight or flee. Cortisol also diverts energy away from certain systems in the body, that would hamper the ‘fight or flight’ response, such as the immune system, the reproductive system and the digestive system.
This stress response system is self-regulating via a negative feedback loop. Once the threat has passed, the sympathetic nervous system switches back to the parasympathetic nervous system (rest & digest) and stress hormone levels return to normal and the body returns to homeostasis. However, in the case of chronic stress, the system is constantly stimulated and doesn’t get the chance to return to homeostasis.
Our stress response system is amazing and would have saved many lives, but it’s designed for more short-term acute stress; not the constant chronic stress many of us are exposed to in modern life or the toxic stress from unprocessed trauma. Over time, the constant stimulation of the ‘fight flight’ system causes havoc on the human body, resulting in the following issues: anxiety, depression, digestive Issues, sleep Issues, chronic fatigue, low libido, weight gain, blood sugar imbalance, hormone imbalances, infertility, HPA-Axis Dysfunction (aka adrenal fatigue), thyroid imbalances, Inflammation, brain fog, lowered immunity & high blood pressure.
This is why it’s so important to address unprocessed trauma and reduce stress as much as possible in our daily lives.
