The car next to you suddenly veers over to your lane. You hit the brakes and it sails ahead. No harm done — except your muscles tense, your heart is pounding, and you are breathing faster. A cascade of stress hormones has produced a well orchestrated set of physiological changes sometimes called the “fight or flight response.” Over the years, researchers have learned how and why these reactions occur, and have gained insight into the long-term effects stress has on physical and psychological health, reports the March 2011 issue of the Harvard Mental Health Letter.

The fight or flight response began as a survival mechanism that helped humans (and other mammals) react quickly to life-threatening situations. In the modern world, repeated activation of the stress response takes a toll on the body, contributing to high blood pressure, the development of artery-clogging plaque, and brain changes that may contribute to anxiety, depression, and addiction.

Many people are unable to find a way to put the brakes on stress, notes Dr. Michael Miller, editor in chief of the Harvard Mental Health Letter. Chronic low-level stress contributes to a variety of health problems. You can't always get rid of stress, but you can learn techniques to counter it. These include:

• The relaxation response. Deep abdominal breathing, focusing on a soothing word, visualizing tranquil scenes, repetitive prayer, yoga, and tai-chi can ease stress. These approaches are worth trying, but for most people are not a cure-all.
• Physical activity. Exercise deepens breathing and helps relieve muscle tension. Movement therapies combine fluid movement with deep breathing and mental focus, all of which induce calm.
• Social support. Friends provide a life-enhancing social net; their emotional support helps sustain us at times of stress.

Read the full-length article: "Understanding the stress response"