How are viruses bad for humans?

Well i am studying viruses at uni so,

they are bad cos they can spread through your body and almost kill you.

so u need to wash your hands after eating or even toucing something. even if u think it is clean.

there will always be some sort of germ on everything.

so to prevent this i carry around detol!

simple!

Im not studying Viruses, but I know a litle. And not al viruses is leatal, in fackt (wonderfully) they are also used to save life, we do also use virus that is created in labs to get imune to the virus that harm you. a virus do what it is programed to do. we have as far as I know not been able to take the full out of that.

some virus is bad and some are not that bad I gues.

but. if you are talking about the bad ones, its because they are infekting a cell to reproduse, they change the genes so that they make more of them.

the worst part is that it is hard for us to treat, most medicins is ineffctive and they can change and evolve fast. that is also why you see some movies where a virus have gone to the next level, and changed humans to Zombies(resident evol) or supre human(some heros from marvel is there) and we also have retro viruses(spider man). but this is today siensfiction.

o the best defence to a virus is also our body, the imune system we got can if met whit the right vacine take down the most of them. its almost the only defence.