With a viral epidemic encircling the globe this information may not quell fear, it won’t make those who are ill feel better but it will explain how our miraculous mind-body is ultimately trying to keep us safe.
Your body sets priorities when fighting germs
The human immune system is a complex set of mechanisms that help you suppress and eliminate organisms — such as bacteria, viruses and parasitic worms — that cause infection.
1. Activating the immune system, however, costs your body a lot of energy. This presents a series of problems that your brain and body must solve to fight against infection most effectively. Where will this extra energy come from? What should you do to avoid additional infections or injuries that would increase the immune system’s energy requirements even more?
2. Fever is a critical part of the immune response to some infections, but the energy cost of raising your temperature is particularly high. Is there anything you can do to reduce this cost?
3. To eat or not to eat is a choice that affects your body’s fight against infection. On one hand, food ultimately provides energy to your body, and some foods even contain compounds that may help eliminate pathogens. But it also takes energy to digest food, which diverts resources from your all-out immune effort. Consuming food also increases your risk of acquiring additional pathogens. So what should you eat when you’re sick, and how much?
Health care providers often treat symptoms as side effects of having an infectious disease. But as it turns out, these changes may actually be part of how you fight off infection:
- Fatigue reduces your level of physical activity, which leaves more energy available for the immune system.
- Increased susceptibility to nausea and pain makes you less likely to acquire an infection or injury that would further increase the immune system’s workload.
- Increased sensitivity to cold motivates you to seek out things like warm clothing and heat sources that reduce the costs of keeping body temperature up.
- Changes in appetite and food preferences push you to eat (or not eat) in a way that supports the fight against infection.
- Feelings of sadness, depression and general wretchedness provide an honest signal to your friends and family that you need help.
(“Of course these changes depend on the context. While it may make sense to reduce food intake to prioritize immunity when the sick individual has plenty of energy reserves, it would be counterproductive to avoid eating if the sick person has malnutrition or on the verge of starvation.”)
Sickness as an emotion
How does your body organize these advantageous responses to infection?
Anthropologists suggest that ” . . . humans possess a regulatory program that lies in wait, scanning for indicators that infectious disease is present. When it detects signs of infection, the program sends a signal to various functional mechanisms in the brain and body. They in turn change their patterns of operation in ways that are useful for fighting infection. These changes, in combination with each other, produce the distinct experience of being sick.”
“This kind of coordinating program is what some psychologists call an emotion: an evolved computational program that detects indicators of a specific recurrent situation. When the certain situation arises, the emotion orchestrates relevant behavioral and physiological mechanisms that help address the problems at hand.”
Some of these coordinating programs line up nicely with our understanding about what makes up an emotion. We understand the emotion of fear when in reality or imagination we think we are threatened by a threat OUTSIDE our body. For example:
“Imagine you’re walking through the woods, thinking you’re alone, and suddenly you are startled by sounds suggesting a large animal is nearby. Your pupils dilate, hearing becomes attuned to every little sound, your cardiovascular system starts to work harder in preparation for either running away or defending yourself. These coordinated physiological and behavioral changes are produced by an underlying emotion program that corresponds to what you might think of as a certain kind of fear.”
Other coordinating programs have functions and features that we might not typically think of as “emotional.” The emotion of “feeling sick” is triggered by pathogens that threaten the INSIDE of our body:
“This way of thinking has helped researchers understand why some emotions exist and how they work. For instance, the pathogen disgust program detects indicators that some potentially infectious agent is nearby. Imagine you smell the stench of feces: The emotion of disgust coordinates your behavior and physiology in ways that help you avoid the risky entity.”
“These coordinated physiological and behavioral changes are produced by an underlying emotion program that corresponds to what you might think of as a certain kind of fear.
Some psychologists suggest these emotion programs likely evolved to respond to identifiable situations that occurred reliably over evolutionary time, that would affect the survival or reproduction of those involved.”
The next time you “feel” sick try to remember your mind-body wants you to survive.
This article was originally published on The Conversation by Joshua Schrock.