From Old English 'wyrgan' (to strangle), from PIE *wergh- (to twist) — mental anxiety sense is only 19th-century.
To feel anxious or troubled about actual or potential problems.
From Old English 'wyrgan' (to strangle, to choke), from Proto-Germanic '*wurgijaną' (to strangle), from PIE *werǵʰ- (to twist, to bind). The original meaning was violent and physical — to seize by the throat and shake, as a dog worries a bone. The shift from 'strangle' to 'harass' to 'cause anxiety' to 'feel anxiety' took place gradually over
When you say 'the dog is worrying a bone,' you are using the word in its oldest sense — to seize and shake something with the teeth. The Old English 'wyrgan' meant 'to strangle,' and German 'würgen' still means 'to choke, to retch.' The mental sense ('to feel anxious') only appeared in the 19th century