I leave the strong weak
I stop many in their tracks
My presence is contagious
I'll give you a heart attack

Give me an invitation.
Yeah, you can be the host
I'll eat you up from within
Looks like you seen a ghost

Parasitic emotion
Only care if I survive
Surround you with commotion
Hypothalamus joyride

Adrenaline is pumping
Breathe in and out fastpaced
Heart begins a-thumpin'
Muscles staining just in case

I treat many on their deathbed
And some I give a high
Others I make drop dead
So tell me,

What am I?