Author: Vienna M Doenni, M.Sc.
I woke up this morning with a pounding headache, running nose, a cough and absolutely no desire to get out of bed. We are approaching winter and I guess it is now cold season. But why exactly do I need to feel this bad, when all I have is a common cold? During my bed-bound research, I found out, that researchers from all kinds of disciplines, from evolutionists to neuroscientist, have tried to figure out the advantages and mechanisms of feeling like crap.
The “Survival of the Sluggishest” Principle
From the evolutionary perspective it seems simple: you are sick and you may not be on top of your game, so stay home or you will get eaten. Animals who did not display appropriate lack of mobility and energy were doomed to experience Darwin’s survival of the fittest (or in this case sluggishest) and got eliminated from the population. Or even worse, they infected their entire herd, flock or pack and dragged everybody down the evolutionary ladder with them. To follow that logic, I feel sluggish and tired to protect the rest of you from my germs.
Behind the Scenes of the Common Cold
The second reason why I will likely not leave the bed today is -according to biologists and immunologists - that I need all my strength to fight the infection. That means I have to heat up my body to make it uncomfortable for bacteria (yay I have a fever L) and pump out white blood cells that clean up the mess (yay nasty slime everywhere L). That all takes a lot of energy that I can’t waste by running around and doing enjoyable things.
The Science of Slowing Down
Apparently, there are really good reasons why I am feeling like I am but how can an inflammation tell me to slow down COMPLETELY against my will? Here neuroscientists have an answer; that question has occupied them for a few decades. According to their research, bacteria and viruses trigger the release of big proteins, called cytokines, from the liver, which then travels through the bloodstream to signal to the brain. Thus when I got sneezed at the other day by that lady on the train, those bacteria made it through my lungs into the blood, multiplied on their way and ended up at my liver. There they triggered the release of cytokines that then signaled to the brain to “slow down”, release prostaglandins to heat the body up and activate other immediate response mechanisms to deal with the bacterial invasion.
Now when will I get better?
While my body is busy starting its emergency response plan to preserve energy and remove bacteria, it also initiates ways to not overshoot the target. While some cytokines initiate inflammation, there are others that will decrease it, to maintain a balance and fine-tune the response. At the same time, they trigger the release of the “stress hormone” cortisol to decrease the inflammation and at the same time making me stressed about being sick. In case of emergency adrenaline and cortisol can kickstart the system to e.g. get away from the imminent threat or to master a task that is very stressful, such as exams.
In conclusion, while I feel bad and stressed about being sick, my body is already working out a way to make me better and will make sure I can run away from a tiger or write the next exam if I am only stressed enough about it. Great; does someone have a tissue, please?