What am I?

From JokeADay:

I shall seek and find you . . .

I shall take you to bed and control you . . .

I will make you ache, shake, and sweat until you grunt and groan . . .

I will make you beg for mercy . . .

I will exhaust you to the point that you will be relieved when I leave . . .

And you will be weak for days . . .

What am I?

(click more to find out the answer)

The Flu