Lyric discussion by psyconius 

Cover art for With Teeth lyrics by Nine Inch Nails

I love that most Nails songs can have so many meanings depending on who is listening and the place they are in life.

The obvious theme here is a woman/relationship, but I agree with a few others here that think it can be applied to anything that someone loves that hurts them. Drugs ring a bell here. A few lines in the song are very close to normal drug references and/or their effects on a person.

I put up a comment on Genesis - Tonight, Tonight, Tonight with the same sort of vague interpretation of being addicted to SOMETHING. The songs are closely related and were blatantly pointed out to me by the Kleptones mashup containing both songs :)

My Interpretation

@psyconius very much could be interpreted as about a lover or drug ... love is a drug??