[ad_1]
Winter illnesses are all around us right now – from the common cold, COVID-19 and flu to sore throats and stomach bugs. They all have one thing in common: They can make you feel sad. These illnesses often come with fatigue, loss of appetite, and difficulty concentrating. Sufferers often want to be left alone, and many also experience sadness and anxiety. (See Photos: From Influenza to Pneumonia: 5 Common Winter Illnesses; How to Prevent)
Researchers have revealed why this is so. When your body is attacked by a pathogen, some of your immune cells recognize the pathogen and take action to eliminate the threat. To be successful, they need to unite with other immune cells as well as many organs in your body.
To do this, they secrete specific proteins, called cytokines. These are messengers that communicate the presence of a pathogen throughout your body, including your brain.
Once the cytokine signal reaches your brain, it triggers changes in the activity of many brain structures. This causes fever to develop, but that is not all.
These brain changes also cause you to feel and act differently: You’re less motivated to do the things you usually like and prefer to be alone and in bed. Ultimately, you feel tired and have less appetite. But you may also be more sensitive to negative stimuli, which can make you easily sad and anxious.
This means that the psychological experience of illness is not generated solely by your brain or the pathogen – it seems to be generated by your own immune system.
make people sick for a day
How can we be sure that feelings of illness are actually caused by our own immune system and not by a pathogen? Researchers have actually shown that such feelings can be induced even without the presence of any true pathogen.
My research group, and a few others in the world, deliberately activate the natural immune defenses of healthy and young volunteers, without using a pathogen.
In several of our experiments, we injected more than 100 study participants with a small dose of lipopolysaccharide, a component of the membrane of Escherichia coli bacteria. Because immune cells recognize this component as a pathogenic threat (although no actual bacteria are actually present), they become activated and produce cytokines.
As during an actual infection, but without the presence of the pathogen, cytokine signals reach the brain and trigger feelings of illness (collectively called “sickness behavior”) as well as behavioral changes.
Interestingly, our participants reported similar symptoms – malaise, fatigue and body aches – without fighting the infection.
The participants said that they would rather be at home than in our study room, and they were no longer interested in doing the various tasks we asked them to do. And although they were not particularly anxious or depressed before the injection, many participants reported feeling anxious and depressed afterward.
Because there were no actual bacteria in the blood, and because the liver and immune cells rapidly clear bacterial components from the blood, the production of cytokines lasted only a few hours, usually five to eight hours. And feelings of illness, including intense negative emotions that had arisen just hours earlier, also diminished within this time frame.
Why do we feel sad during transition?
Now the question is, should we feel sick during the infection? And if so, why? Well, even if you aren’t fully aware of it, fighting off a pathogen requires an incredible amount of energy. Both the activity of your immune cells and the increase in body temperature are heavily affected. The only way your body can cope with these high energy demands is to strongly reduce the activity of those organs that are not immediately needed.
Feelings of illness ultimately ensure that your body’s energy is not used for activities that are not essential at the time of infection – you need to stay calm and stay at home. Thus, they help you avoid using your muscles and even your brain – causing you to skip the gym or extensive study. And feeling depressed and anxious prevents you from going out and partying with your friends.
Feelings of illness are therefore likely to be beneficial in the fight against the pathogen.
This is probably why all vertebrates, and even invertebrates like bees and ants, behave the same way we do during infection.
Therefore, it can be difficult to think of a way out of despair when you are sick. But I hope this insight will help you get rid of negative thoughts when faced with winter illness. Don’t feel guilty or anxious about feeling sad – it’s natural.
A healthy way to respond might actually be to accept these feelings as a normal reaction of your body when it needs to fight pathogens. If you don’t do this, you will likely go into a cycle of guilt, fear and negative emotions that will only get worse.
And by the way, if you feel sore in the days after vaccination… don’t worry – it means your immune system is working.
[ad_2]
