How High Stress Leads to Reduced Brain and Body Functioning

February 03, 2023 by Mari Pfingston-Bigelow

We all know the feeling of mounting stress - it starts as a little weed, easy enough to identify, clasp with a few fingers, and pluck from your mental garden. But with too many weeds of stress and too little time to tend the garden, weeds start to take on a life of their own and can curtail the natural growth of our sprouts and blossoms. Left unattended for too long, weeds shift the entire ecosystem and change the garden entirely.

This analogy relates to the development of stress in our brain and the long term effects that chronic stress has on our body and mind. Short-term stress is normal and healthy, developed as a mechanism for survival and for coping with unpredictable environments. But when stressors are long-term and unrelenting, we stay in a chronic state of stress and depletion. This leads to deterioration of both mental health and physical health, decreasing our capacity to function and adapt in our day-to-day life.

 Effects of Stress on the Brain

 When we perceive a threat or other stressor is in our midst, our brain and nervous system immediately reacts. It shifts us into fight-or-flight mode, the response of our sympathetic nervous system (SNS), leading to a rapid-fire series of events. The ‘fear center’ of our brain, the amygdala, is activated and sends distress signals to the command center of the hypothalamus. This creates a cascade of activity within our nervous and endocrine systems, including the release of the stress hormones adrenaline and cortisol.

 When this happens on a short-term basis, stress does what it’s supposed to do; sharpens our brain’s functioning, motivates us into action, and promotes quick response times. But long-term stress has an entirely different effect.

 When this stress response system continues for too long, it can greatly decrease our ability to think, process, adapt, retain memory, and discern appropriate action and behavior. This is largely because the consistent activation of the amygdala lowers the functional capacity of other parts of the brain, including the command center of the prefrontal cortex. This means that many parts of cognitive function are affected, including memory, learning, problem-solving, creativity, and flexible thinking.

 Not only that, but stress can kill brain cells and reduce the physical size of the brain, shrinking the prefrontal cortex while enlarging the amygdala. This means that our brains become even more receptive to stress, strengthening the related neural pathways and increasing the likelihood that we’ll respond similarly in the future. This also means an overall lowered emotional state and erosion of mental health, which can either lead to or worsen clinical depression.

Stress Management

Although all of these long term effects listed together can seem frightening, it’s ultimately a tool of empowerment. If we know the mental and physical symptoms of chronic stress, we can more easily and readily take proactive action to change our mental habits and external environment. 

 It can be easy to develop tunnel vision when you’re in the thick of it, not even noticing how much stress you’re experiencing. But the more you have knowledge, self-awareness, and tools for stress prevention on your side, the more you can avoid ever getting to the point of serious physical or mental health damage.

 For information and tools about how to better manage stress, see our other blog posts about using the power of humor and eliminating scarcity thinking.