Lyric discussion by pasosports 

Cover art for My Iron Lung lyrics by Radiohead

Iron Lung is an extended metaphor for a 20th century sell out song. The lung gives the band some breathing room and keeps their popularity up to par. The lung however is Iron; cold and shallow. It's not real. Not real Radiohead.

Thom was suffering from writers block and he understood that the band needed a hit song. Frankly he hates the track he says so in the lyrics. But it ended up the song was a huge hit and people listening to it on top 40 didn't even realize that the lyrics are just him trashing his own song. Priceless.