It's just a cold. But even though I know I'm not horribly ill, I feel this overwhelming need to skip work, ignore my family and retreat to the far corner of the sofa.
I'm not being a wimp, it turns out. Those feelings are a real thing called sickness behavior, which is sparked by the body's response to infection. The same chemicals that tell the immune system to rush in and fend off invading viruses also tell us to slow down, skip the eating, drinking and sex, shun social interactions and rest.