Why does a cold literally drain the engery out of you?

Question

I can barely stay awake typing this.

Answer 1

Your body is working hard to fight off the virus. It's just like being tired after a work-out; your T-cells are expending a lot of energy to fight whatever you've got. That is one of the reasons you have to be sure to keep your strength up by eating normally, even if you don't feel like it - it helps you get over the sickness quicker.

Answer 2

Normally,when you are ill the body is fighting off the infection, whatever that might be. The body is tired which is a reason for getting the greatest amount of rest possible.