The Big Picture

Stress and the Body’s Response Part I

How your body responds to stress


Recently it seems everywhere you look someone is talking about stress. The usual implication is that stress is bad for our health. Many conditions such as ulcers, migraines, insomnia, anxiety, depression, weight gain, and fatigue are referred to as stress-related. Even cardiovascular disease, in particular heart attacks and strokes, are thought to be brought on by stressful conditions. Think of the common phrase “I nearly had a heart attack!” after being startled.

The statements above may be generally accepted as true, but what stress is and how it could have such a dramatic effect on our general health is really not well outlined. I think it is important to describe stress and its effect on the body in an understandable manner (in “layman’s” terms). First I will define stress in the broadest sense of the word. I will then talk about the importance of the stress response. Finally I will outline general categories of various stressful events also referred to as stressors. Over the next few posts I will continue with the topic of stress. I will talk about how a acute stress response affects the body. I will continue to describe the implications these stresses can have on the body, how their effects can be cumulative, and how chronic stress can have an effect on long-term health. This information is important for making responsible lifestyle choices which affect our general health.

What Is Stress?

The body undergoes stress when it encounters any challenge that is not easily overcome.

Sometimes your immediately available energy supplies are insufficient to meet the demands imposed by a stressor. In these situations, back-up mechanisms to generate more energy become active. These mechanisms can generally be thought of as defensive mechanisms. When in this defensive state, we experience a shift in the metabolic function of the body. This is our body’s stress response.

One of the first signs of this stress response is the production of adrenaline. This hormone allows for the release and use of energy stored for emergency use. There is also a shift in the nervous system which regulates the body’s energy use. This neurological change allows for energy to be used more by the muscles, sensory organs such as the eyes, ears and nose, and the more primitive parts of the brain, which have developed to react rapidly and instinctively to the environment. Brain function is shifted away from the portion of the brain used for long term problem solving and complex thought processing. Energy use is also lessened in the organs used for digestion, detoxification, and tissue maintenance.  This state is commonly referred to as the “fight or flight” state. Signs that this stress response has occurred include a rapid heartbeat, quickened breath, skin flushing, tense muscles, becoming acutely aware of a specific concern or danger, and difficulty thinking of much other than the specific subject which has caught your attention. Nausea, diarrhea, heart burn, abdominal cramping, difficulty swallowing, dry mouth and eyes, are all possible signs of this state as well, but typically are due to a significant trauma or a degenerated body unable to handle stress well.

The stress response has developed in humans for the occasions when a situation is life-or-death. But nowadays, due to our contemporary lifestyles, many people live in a state of chronic stress, which means that instead of the bodily changes of stress discussed above being a rare occurrence, they are more a part of our daily lives and thus, they have a dramatic effect on our health. This is significant, and I will come back to this in a future post describing the implications of stress on health.

What Types of Challenges Are Stressful?

The challenges which can cause a stress response are so various it may seem as though they are unrelated. The body however responds the same to each of them. Though it is impossible to truly separate stressors from each other, in order to aid our exploration of various types of stress, I have developed five general categories that include the different types of stresses we experience. These categories are mental, physical, emotional, nutritional, and toxic. In reality, no matter which category is the primary or triggering stressor, we will experience the effects of this stressor in all five areas. This will be discussed in greater depth in future posts.

Mental: I start with this category in part because, of all of them, it is the most commonly thought of as stress. When I ask clients and friends about the sources of stress in their lives, most reply that work is their biggest stressor. This makes sense because sustained mental focus and effort, particularly in a competitive environment, is obviously challenging and the risk of failure is apparent. Mental stressors are those in which the thought process provokes the stress response. While this is easily described in terms of office work or schooling due to the demanding contemplation which can be required of problem solving and creative thought production, there are many other mental stresses. Relationships with others, communication, and self-presentation are common examples. Think of thoughts like “What should I do for my birthday this weekend?”, “What if she doesn’t like what I am wearing?”, or “I hope I say the right thing!” The term “worry” well describes this action of mental stress. How this challenge relates to an increased need for energy and the production of adrenaline is much less obvious. The ability to predict a potential threat is just as important as responding to an actual threat, so our body engages our stress response preemptively in anticipation of a threat. I will elaborate on the importance of this in my next post.

Physical: Though all stress fits into this category (as stress is measured by changes in the body), this category specifically describes events like hiking up a hill, working out, or an injury such as a broken bone or cut. These events obviously require an immediate increase in energy and have an obvious beginning, middle and end. I will use this to exemplify the effect of stress on the body in my next post.

Emotional: The importance of separating the emotional from the mental challenge is best described by the fact that emotional processing occurs in a primitive part of the brain. We feel a response to any sensory information including touch, smell, taste, sight, and sound before we form complex thoughts that allow us to plan a response. This is due to the fact that the emotional brain precedes the cognitive portion of the brain in the signal chain. This means that any information will first be brought into the emotional part of the brain before the cognitive part. If the emotional brain perceives a threat, it will trigger the fight or flight response, before you have a chance to think. Examples of emotionally traumatic events are the death of a loved one or witnessing violence or even a horror film.

Nutritional: This is a more complex category. A nutritional challenge can be in the form of a missed meal or insufficient intake of calories. It can also be a deficiency of a specific nutrient, such as protein or vitamins and minerals. A third possibility is that the foods being consumed are difficult to break down and create a demand on the body which exceeds the available energy for digestion.

Toxic: A good example of a toxic stressor is the ingestion of or environmental exposure to a poison such as arsenic or snake venom. The body will have a certain ability to resist the poison, called tolerance. If the poison level exceeds the tolerable threshold, it will become stressful and require significant action from the body’s immune and detoxification systems to remove the substance before too much damage occurs. Other substances which fit in this category are parasites, irritating portions of foods, microorganisms, and byproducts of bacteria and viruses. Even some of the byproducts of our own metabolism and bodily functions are toxic, such as lactic acid and urea.

The information above offers a way of understanding what stress is and how different stressors can appear as we encounter them in life. Later, I will describe the way that the various stressors instigate the stressed state. I will also speak about the body’s process of restoration from this state and how important it is that we have the ability to respond to challenges encountered in this way.

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