Effects of Stress:
What Happens When We Feel Stressed?

The news is not good. As if the subjective experience of being stressed out were not enough, over time, stress wreaks major havoc on our health. To understand how, we have to first understand how stress works.

So what exactly happens to us when we feel stressed?

Collectively, these changes are known as the "fight or flight" response. To get them done, the body utilizes a series of complex interactions among the brain's hypothalamus, the pituitary gland, and the adrenal glands.

The "fight or flight" response

Noradrenaline is a neurotransmitter that speeds communication between brain cells. This makes us more alert and aware. The extra noradrenaline also triggers the sympathetic region of the autonomic nervous system to tell the adrenal glands to begin releasing both adrenaline and noradrenaline.

Raised levels of adrenaline and noradrenaline in turn tell the pancreas to release a hormone that raises our blood sugar level.

Meanwhile, the hypothalamus starts talking to the pituitary gland, telling it to release another hormone that tells the adrenal glands to release cortisol, also known as the "stress hormone." Cortisol plays a big role in the body's stress response. It increases blood pressure and blood sugar, reduces excretion of water, stimulates secretion of gastric acid, reduces immune system response, and, in conjunction with adrenaline, helps the brain form memories of short-term emotional events.

The hypothalamus also causes the pituitary to release hormones that suppress the reproductive system, make us retain water, and stimulate the body to release endorphins and enkephalins, which act as pain suppressors.

What does "fight or flight" do to our bodies?

Since these acute physical threats were relatively few and far between, we would not have to run our bodies this hard for an extended period of time, and would have adequate time to recover completely.

Modern stress is different, but we respond the same

Nowadays, we are less likely to face short-term physical threats and more likely to face longer-term social and psychological ones.

Evolutionarily speaking, a few hundred years isn't enough time for us to have developed stress responses that are more appropriate for modern stress.

That's really the crux of the problem.

Because our bodies can't distinguish whether the thing that is stressing us out is a physical threat or a social or psychological one, we get the "fight or flight" response regardless.

If the threat is not someone attacking you but a looming work deadline, you're not going to punch someone or run for your life (though you may certainly feel like it!). Instead, you sit at your desk for hours, keyed up for action you never take. Physiologically speaking, the effects of stress leave you "all dressed up with nowhere to go."

Once we are undergoing a "fight or flight" response, but not actually fighting or fleeing, we may react to the effects of stress by becoming angry or argumentative. This can be seen as a modern manifestation of "fight." On the other hand, we may withdraw from others, watch television, or turn to alcohol, nicotine, or other drugs to relax, the modern version of "flight."

Whether a person chooses to fight or flee may also be a matter of gender. Studies indicate that men are more likely to respond to the effects of stress by putting up a fight, whereas women are more likely to try to escape from or defuse the threatening situation. Women also become protective of their children and seek help from others when under threat.

In any case, today's "fight or flight" response is not often followed by physical action, so the effects of stress linger. Because you don't discharge them by fighting or running, all the hormones that have been activated continue to sit in your body, affecting your heart rate, blood pressure, blood sugar, digestion, immune system, and all the rest, until they gradually dissipate and you return to a relaxed state.

Modern stress lasts longer

Over time, all this readiness wears your body down. We're not designed to run in emergency mode all the time. This is where the connection between stress and health comes into play. After extended exposure to stress, you can begin to experience nausea, dizziness, chest pain, digestive problems, headaches, insomnia, aches and pains, diarrhea, constipation, anxiety, more frequent colds, even loss of sex drive.

Even more troublesome, other effects of stress are to exacerbate existing medical conditions, and cause or contribute to new ones.

Managing "fight or flight" for better health

Unfortunately, that's not going to help today's humans. But there are things we can do to better manage the host of changes brought about by the "fight or flight" response. Good nutrition, proper rest, exercise, and learning to relax can all help our bodies recover sooner from the effects of stress.

Even better, by paying attention to how we feel, we can learn to recognize the beginnings of a "fight or flight" response, which can allow us to take steps to defuse it early.

And when a car swerves into our lane, or a stack of boxes starts to fall on us, we can still thank Mother Nature that our bodies know how to instantaneously prepare us to react quickly.

Photo by alancleaver_2000 via Flickr, used under a Creative Commons license.