It was originally leaked online by the band, and later given to iTunes as a digital download before Infinity on High was released. In addition, a web-exclusive video was released, but later saw televised airplay on Music Choice On-Demand. The song debuted on the US Billboard Hot 100 at number No. 81 on the strength of digital downloads and moderate airplay, also coming in at No. 67 on the defunct-Pop 100.
"The Carpal Tunnel of Love" has been referred to as "a prime slab of what the boys have become famous for: highly caffeinated pop-punk mixed with a little white-boy soul and some hard-core yelping." The song features Stump singing in a falsetto in the chorus over Trohman’s "crunchy" guitars, as well as a breakdown in which Wentz employs death growl-style vocals, similar to how he used to in his former band, Arma Angelus.
Some elements of the lyrics were alleged to have been stolen from the works of Give Up the Ghost/Some Girls singer and lyricist Wesley Eisold, who sued the band for copyright infringement after the song was released. Eisold was credited as an "inspirador" in the album liner notes in all versions of the albums. Fall Out Boy settled out of court. The song title is a combination of carpal tunnel syndrome and the tunnel of love carnival ride.
On February 5, 2007, the music video was made available on Fall Out Boy's website and was directed by Happy Tree Friends creator Kenn Navarro. The video features Happy Tree Friends characters and cartoon versions of the band in a plot where Cuddles and Giggles have fallen in love, and Cuddles' attempts to express his love to Giggles. The video concludes with most of the characters in the video, including the Fall Out Boy members, being killed in a graphic and ultraviolent manner. The only character not killed is the unseen bus driver that drives Cuddles, Giggles, and Lumpy to a cafe.