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The impact of stress on your body

Feeling a bit of stress in your life? If you're not, you're a rare breed. We're surrounded by stress day in and day out—our work, our relationships, the economy, the commitments we make to ourselves and others, the incessant use of gadgets that make our work day (and I'm not just talking about employment) practically endless with little down time to just sit quietly and reflect. Who wouldn't be stressed?

The question is how much is too much? And that's where most people get a failing grade. They don't recognize the toll stress takes on their body nor do they notice the bright red flashing warning lights signaling the danger until it's too late. By then, they're so burned out that it's hard to recover.

But it doesn't have to get to that point. In this two-part series, you'll learn how stress affects your body and learn to identify the warning signs of too much stress early enough so that you can reverse its negative effects and live a happier and healthier life.


Stress is a normal physiological reaction to a perceived physical or psychological threat. As an instinctual self-protective mechanism, when we sense a threat, our bodies react in a way that helps us defend against the threat. This response, labeled the "fight or flight" response by Walter Cannon in the early twentieth century, is involuntary. Our bodies do it automatically and immediately whenever we sense danger in our environment. It sets into motion a complex series of physiological events designed to help us survive the threat.

Internally, the sympathetic nervous system responds by releasing a flood of adrenaline, which prepares our bodies to react quickly to fend off or escape the danger. Endorphins are released to temporarily increase our threshold for pain. Blood vessels in our skin constrict to prevent potential blood loss. Sweat glands open to cool our hard-working bodies. Blood flow is diverted from less vital systems, like the digestive system and the kidneys, to more vital organs like the heart. Heart rate increases, muscles tighten, and blood pressure rises. Breathing becomes more rapid, helping to bring more oxygen to our muscles. Our senses become sharper, and our focus increases. This, in turn, improves our reaction time and increases our strength and stamina.

All of these things occur within seconds to significantly increase our chances for surviving a life-threatening event or helping someone else survive a life-threatening event. Then, once the threat is gone, our system returns to homeostasis. Or at least that's the way it's supposed to work.

From an evolutionary perspective, this "fight or flight" response was very adaptive in the sense that it kept our ancient ancestors from being eaten by wild animals. In more modern times, not so much. The response is still helpful in those situations where we need to escape a dangerous situation (like maneuvering safely through a busy intersection on foot) or focus on an important task (like a big exam). But very little of the stress we experience today is in response to a mortal threat.

The problem is that our bodies can't tell the difference. From a physiological perspective, a threat is a threat, mortal or otherwise. So whether we're trapped in a ravine with a hungry mountain lion or trapped in our office with a ferociously overflowing in-box, the body's response is the same—prepare for battle.

That would probably be okay if we could run out of our offices (the "flight" response) to escape the ferocious in-box. But we can't (assuming you want to keep your job). We just have to suck it up and adjust. We can't take a baseball bat to our computer when the Internet is running slow (the "fight" response), although that would probably make us feel good. We just have to sit there and wait and wait and wait and ... you get the picture. The body just keeps reacting to all these "threats" and there's no real chance for it to return to normal. Simply put, the body isn't designed to handle that much stress for that long a period of time.

Endocrinologist Hans Selye, recognizing that prolonged stress produced a pattern of reactions in the body that led to increased infections, illnesses, and sometimes even death, developed a model he called the General Adaptation Syndrome (GAS) to describe and explain this process. The GAS has three stages. The first stage, the Alarm Reaction, is basically the "fight or flight" reaction described by Cannon. The second stage, called Resistance, is the phase in which the body tries to adapt to the stress to prevent illnesses and infections. This causes our immune system to kick into overdrive. But it can't do this indefinitely, which leads to the third stage, Exhaustion. Exhaustion results when the body's resources become depleted by too much stress. On a physiological level, the body basically burns out, which is why exposure to chronic stress can lead to serious health and emotional problems or exacerbate preexisting conditions.


With that said, we don't all respond in the same way to stress. We each have our own trigger points for stress. People who are more laid back tend to have higher trigger points before the "fight or flight" response kicks in. People who are more edgy or sensitive tend to have lower trigger points.

Our specific reactions to stress also are different. Some people experience headaches and depression. Others develop ulcers and anxiety. Some use uppers to stay awake and alcohol to fall asleep. Others yell, worry, or cry. But in general, reactions to stress can be broken down into physical symptoms, psychological difficulties, and negative behavioral changes (all of which are described in Part II of this series).

Stress also can be mediated by a number of different factors unique to our individual circumstances. For example, people who have strong social support networks—friends, family, and colleagues that they can count on to help them through tough times—tend to be more resistant to the effects of stress. Personality also plays a role. And interestingly, knowledge about stress can mediate its impact. Just by being educated about the nature of stress, its impact, and ways to reduce it increase the likelihood that you will act in ways to decrease your stress.

© 2012 Sherrie Bourg Carter, All Rights Reserved

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Sherrie Bourg Carter is the author of High Octane Women: How Superachievers Can Avoid Burnout (Prometheus Books, 2011).

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