Brain cells bombarded by stress signals have little recovery time and eventually start to shrink and cut connections to other brain cells.  The network that coordinates our thoughts, emotions and reactions thus starts to rearrange.  Over time, entire regions of the brain can grow or shrink.  That may explain why studies have linked higher levels of stress hormones with lower memory, focus and problem-solving skills.

Studies have also illustrated the strong link between insomnia and chronic stress.8 According to APA's Stress in America survey, more than 40 percent of all adults say they lie awake at night because of stress. Experts recommend going to bed at a regular time each night, striving for at least seven to eight hours of sleep and eliminating distractions such as television and computers from the bedroom.

Over the years, researchers have learned not only how and why these reactions occur, but have also gained insight into the long-term effects chronic stress has on physical and psychological health. Over time, repeated activation of the stress response takes a toll on the body. Research suggests that chronic stress contributes to high blood pressure, promotes the formation of artery-clogging deposits, and causes brain changes that may contribute to anxiety, depression, and addiction. More preliminary research suggests that chronic stress may also contribute to obesity, both through direct mechanisms (causing people to eat more) or indirectly (decreasing sleep and exercise).