Eli5: What determines which symptoms we experience when fighting a virus? Why do people react differently to the same illness?


I’m currently experiencing my first bout of Covid. Fun! I’ve had very mild respiratory symptoms, no cough, but the bodyaches and fatigue are no joke. Why is it I feel like this and others might be hacking up a lung?

In: 9

COVID 19 attacks the cells in your lungs. If your body doesn’t respond fast enough they can infect and kill a significant portion of those lungs cells. At that point the body responds to the damage with inflammation. The more damage the more inflammation. That inflammation causes us to cough as the brain interprets it as potentially something stuck in our throat or lungs

So the faster your body recognizes and fights the virus the less coughing you will have. But with different viruses there are any number of reasons why people react differently.