The single was issued on 14 April 1980, four months before the album was released, and reached number 16 in the UK charts, remaining in the charts for seven weeks. It was the first single by Bush to feature a non-LP track on its B-side, "The Empty Bullring".

"Breathing" is about a foetus, very much aware of what is going on outside the womb and frightened by nuclear fallout, which implies that the song is set either during a nuclear war scare or a post-apocalyptic birth. The lyrics also refer to the unborn baby absorbing nicotine from the mother's smoking. In an interview that year Bush described the song as her "little symphony", adding that she considered it her best work to date. Bush stated that the information within the song mostly came from a documentary she had seen about the effects of nuclear war, while the tone of the song was inspired by Pink Floyd's The Wall (side three in particular). The song was recorded over three days in early 1980.

The track includes spoken words describing the flash from a nuclear bomb.

The music video features Bush in a womb portraying a foetus.

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