Best Answer: The correct phrase is a wolf in sheep's clothing. It means someone is pretending to have good intentions about something, but they are really up to ...
Like other brain illnesses, anxiety disorders may be caused by problems in the functioning of brain circuits that regulate fear and other emotions. Studies have shown that severe or long-lasting stress can change the way nerve cells within these circuits transmit information from one region of the brain to another.
It's well known that anxiety can cause heart palpitations, and it's believed that the main cause may be an over-awareness of one's own heart, combined with surges of adrenaline that may occur at random in those with anxiety. These types of palpitations often trigger panic attacks.