Jump out of your skin - Idioms by The Free Dictionary
jump out of your skin
jump out of your skin or
nearly jump out of your skin
If you jump out of your skin or nearly jump out of your skin, you are suddenly very surprised or shocked by something. The doorbell made him jump out of his skin. He nearly jumped out of his skin when he saw two rats.
jump out of your skin be extremely startled. informal
jump out of your ˈskin (informal) make a quick, sudden movement because something has suddenly frightened you: When I heard the explosion, I nearly jumped out of my skin. ♢ She nearly jumped out of her skin when somebody banged on the door in the middle of the night.