Among the ideas Stipe set out to explore lyrically were what he described as the "religious-spiritual versus science-technology-modern-age", in addition to an "automatic, unconscious" style.

[10] While the tour was critically and commercially successful, the band was marred by health problems, including an aneurysm suffered by Berry at a show in Lausanne, Switzerland.

[11] After receiving emergency surgery, Berry made a full recovery, although the band had to cancel the rest of their spring tour.

[11] Bassist Mike Mills additionally had to have an intestinal tumor removed in July of that year, whilst in August lead vocalist Michael Stipe suffered a hernia.

[12] In the spring, the band parted ways with longtime manager Jefferson Holt due to allegations of sexual harassment.

[17] Later in March, the band continued work in Buck's home studio in Hawaii, intending to build songs around the backing tracks created in February.

[19] However, sessions booked at John Keane's studio in October and November were cancelled, as the band were unsure of their direction and "couldn't rehearse without a drummer.

[21] Considered both an alternative rock[2] and electronic record,[3] Up is largely defined by the use of drum machines and keyboards, to a greater extent than on any previous R.E.M.

[19] In reviewing the album's 25th anniversary reissue for Pitchfork, Stephen Thomas Erlewine declared it to be Up's "hardest rocking cut".

[2] "Suspicion" has been described by Ryan Leas of Stereogum as a "strange electronic meditation" and "a whisper of a Bond theme in some kind of space lounge".

[19] Erlewine states the song "hums along to an understatedly urgent pulse", while Leas interprets its lyrics as "grappling with technology and faith".

[24] The writing of the song was spurred by Stipe coming up with the lyric "I found a way to make you smile" while sitting in traffic.

[24] Seth Troyer of PopMatters compares the guitar work on "The Apologist" to that of the band's 1994 album Monster, while referring to its lyrics as a "character study" echoing the chorus of an earlier R.E.M.

"[27] Much like "At My Most Beautiful", Leas compares "Why Not Smile" to Pet Sounds–era Beach Boys, while Troyer states the track "begins as a simple acoustic song and explodes into a borderline shoegaze, noise guitar jam.

"[3][26] The lyrics of "Daysleeper" are generally more direct in comparison to other tracks on the album, sung from the perspective of a nightshift worker whose lifestyle causes them to feel isolated and depressed.

[28] Troyer considers "Daysleeper" to be one of the most conventional songs on the album, saying it "chime[s] forth with a catchy pop-rock style that [feels] more like classic R.E.M.

"[26] Tim Peacock of uDiscover Music cites "Diminished" and "Parakeet" as examples of the album's use of experimental instrumentation, with the former including "embellishments of vibes and tabla" and the latter utilizing "Pet Sounds-era organs.

[26] Breaking with a tradition that stretched back to the band's 1983 debut, Murmur, Stipe elected to have his complete lyrics included in Up's CD booklet, a practice he would maintain on all subsequent R.E.M.

[33] However, Up saw more success in Europe, with it topping the charts in Italy, Germany, Austria, and Norway and placing at number two in the UK, Ireland, and Sweden.

[34] This reissue included a second disc with the band's February 1999 live performance for the sitcom Party of Five alongside a DVD with music videos and other material.

Writing for the Los Angeles Times, Mike Boehm found the album to be an improvement from New Adventures in Hi-Fi, praising its "resourceful and cohesive soundscape" and its "passionate take on end-of-the-century malaise".

"[38] Boehm highlighted Stipe's vocals on "At My Most Beautiful" and the album's "two rockers" ("Lotus" and "Walk Unafraid"), while likening "Hope" to "Kraftwerk covering Leonard Cohen's 'Suzanne'".

's most cohesive album since Automatic for the People (1992) and said that their shift toward "mid-tempo, or often no-tempo, hymns and ballads" suited them, accentuating the vulnerability "at the heart" of the band's work.

[36] In a four-star review for Q, Danny Eccleston felt the album would be challenging for casual listeners, but more accessible for fans of the band: "It will certainly sound strange to those who only own Automatic for the People and repeat-play the hits.

records – let's say four – and plays them regularly, should manage to listen to Up without his head exploding or tossing herself off a tall building or any of the weird things people are meant to do when faced with music they don't quite understand.

"[43] Conversely, Pitchfork's original review of the album was more mixed, feeling that the band's change in sound was "contrived and forced.

Writing for AllMusic, Stephen Thomas Erlewine called the album "accomplished and varied", while also noting that the record proved how R.E.M.

"[35] Louis Pattison of Uncut noted the group's embracement of electronica and the aesthetics of hypermodernity, with a dislocated, 'fin de siècle' feel comparable to Radiohead's OK Computer and Kid A (2000), with Thom Yorke of that band citing Up as a touchstone for the latter album.

Pattison added that Up's use of electronics was prescient, as "post-Kid A, groups like The Postal Service and Owl City would work so-called 'emotronica' into a commercial force.