Neurosis formed in late 1985 in Oakland, CA, USA as a hardcore punk band and has since developed an experimental rock sound. The band was founded by ex-Violent Coercion members Scott Kelly (vocals, guitars) and Dave Edwardson (bass, backup vocals) along with Jason Roeder (drums), joined later by Steve Von Till (vocals, guitars), Noah Landis (organs, piano, sampling), and Josh Graham, who does the visuals for their live performances (previously done by Adam G. Kendall).

At the time Neurosis formed, the members sought out a raw hardcore sound which leaned toward the punk side. Their first two releases are widely labeled as hardcore punk; over the years, however, the band has steadily evolved their sound into something that is nearly impossible to label. Neurosis is most commonly described as sludge or experimental. Neurosis has influenced a wide array of artists, including Isis, Mastodon, Gojira, Pelican and Cult of Luna. Many consider the band to be the pioneer of the 'sludge' sound.

With the release of Souls at Zero, their 1992 third studio album, the band started to move away from the hardcore punk genre, adopting more psychedelic and experimental elements while keeping the brutality and the hardcore sound that they were previously known for. The album alienated most of their early fanbase, but also introduced the band to many new listeners. The album was later re-released on their own record label, Neurot Recordings. Neurot Recordings features other sludge-influenced artists such as Isis, Red Sparowes, and Oxbow.

Neurosis members participate in many side projects. Red Sparowes is the most popular project, consisting of members of Neurosis and Isis. Tribes of Neurot is the bands alter ego, and it focuses on dark ambient music. Neurosis & Jarboe was a collaboration between Neurosis members and Jarboe, the former keyboardist/vocalist of the Swans.