Why do you feel weak when you have the flu?

Answer 1

When your body is invaded by things like a virus, the immune system sends out white blood cells (also called leukocytes) to find the infection. The white blood cells release a chemical called cytokines, which is what causes the joint pain seen not just in the flu but with many inflammatory/autoimmune conditions like Arthritis, lupus,inflammatory bowel disease, etc.

I have copied this answer from user njdocisin on Yahoo answers who clearly knows what she's talking about.

Answer 2

You have the flu when your body has been infected with an influenza virus.

It is an infectious disease, so you "caught" it from someone else who was infected with it. The most common way it is "caught" is from direct bodily contact with another person, such as shaking hands, holding hands, kissing, etc. Or you can get it if someone is coughing or sneezing near you without covering their nose and mouth, so the respiratory droplets come in contact with you. You can also get it by just touching something an infected person touched.

Prevention methods include flu vaccinations and frequent hand washing. See more in the related questions below.

Answer 3

Your body is working hard Behind the Scenes to fight off the infection. It uses energy even while you rest, so you don't notice the loss, and consequently are more tired than you should be.

Answer 4

Because your body is tired and you lack nutrients

Answer 5

because you denounced Satan