on June 27th, 2012 2 Comments
Stress is an inevitable part of daily life and sometimes it can feel as though you might crack under the pressure. While you may never be able to eliminate stress completely, you can learn to identify its source and manage it better. This month, Stanford health psychologist Kelly McGonigal, PhD, explores the evolutionary roots of stress and how our stress instincts interact with modern challenges in her Stanford Continuing Studies course.
In the following Q&A, McGonigal discusses the science of stress and how it affects the mind-body relationship, and she offers tips on managing the body’s flight or fight response.
How does stress affect the human body?
The physical stress response is more complex than most people realize. Sure, we recognize this when we’re under pressure. The heart speeds up, our blood pressure spikes and maybe we feel our stomachs churn and our jaws clench. But these stress symptoms are just a small part of a complicated cascade of changes in your brain and body.
It begins when the brain detects – or even just imagines – any kind of threat. It could be to your survival, like realizing a car is about to crash into you. Or it could be a threat to your ego, like getting criticized by your boss. The brain then unleashes a stream of chemicals that shifts the mind and body into emergency mode.
The brain shuts down regions important for long-term planning and juices up regions that help you react quickly and without much thinking. The body sends its resources to the systems that will help you flee from danger or fight to defend yourself (that’s why the heart is pounding!). It takes those resources away from things like digestion, reproduction and healing. That’s a big part of why chronic stress is so harmful for health and can increase risk of heart disease, infections and digestive or metabolic disorders.
At the same time all this is happening, stress hormones released throughout the body are shaping our behavior. The hormone oxytocin is a key part of the stress response for women. It creates the desire to be close to others, to seek social support and hugs and protection. Among men, there may be an increase in vasopressin and testosterone. These two hormones increase the competitive drive and desire to defend yourself and those you care about. And among just about everyone, the stress hormone cortisol makes us crave whatever we are addicted to, from cigarettes to cookies to checking our phones or email.