The domestic music portal site Naver Music described "Symptoms" as belonging to the slow jam genre with influence from Shinee's signature contemporary R&B style.[2] The song was composed and arranged by the international music production team The Underdogs in their first collaboration with Shinee. It also marked their debut in the Korean pop music industry.[2] The lyrics were penned by Shinee's main vocalist Jonghyun.[3]
"Symptoms" was first unveiled through a lyric video uploaded to SM Town's official YouTube channel on October 4, 2013.[4] The first live performance of the song was included in the set-list of the Shinee Comeback Special at Gangnam Hallyu Festival on October 6, in Samseong-dong, Seoul. The performances were streamed on SM Town's YouTube channel.[5] The first broadcast live performance, however, was through Mnet's music show M Countdown on October 10, 2013.[6] This was followed by performances at KBSMusic Bank on October 11,[7]MBCShow! Music Core on October 12,[8]SBSInkigayo on October 13,[9] and MBC MìShow Champion on October 16, 2013.[10]
"Symptoms" received generally positive reviews from critics. Jakob Dorof of Vice considered it one of the best K-pop songs of the year, writing that "the RnB wooze of "Symptoms" feels especially right for 2013".[11]Billboard described it as "an evocative tune that plays up the quintet’s strengths and versatility", lauding it as "one of the best boy band songs ever crafted".[12]
^Seong, Go-eun (October 6, 2013). 샤이니 쇼케이스, ‘강남한류페스티벌’ 컴백에 실시간 접속 폭주… '역시 샤이니' [Shinee's comeback showcase at the 'Gangnam Korean Wave Festival', surge of users... 'As expected of Shinee']. Seoul Economic Daily (in Korean). Retrieved April 14, 2024 – via Naver.
^Yang, Joo-hee (October 10, 2013). "아이유-샤이니-티아라… 오늘(10일) 반가운 가수들의 컴백러시" [IU - Shinee - T-ARA... Today (10th) is the comeback rush]. Seoul Economy (in Korean). Archived from the original on June 7, 2021. Retrieved June 7, 2021 – via Naver.
^Kim, Seong-hee (October 11, 2013). "샤이니, '뮤뱅'으로 컴백..'명불허전' 입증" [Shinee makes a comeback on 'Music Bank']. Star News (in Korean). Archived from the original on June 7, 2021. Retrieved June 7, 2021 – via Naver.
^Jang, Young-joon (October 12, 2013). "'음악중심' 샤이니, 제복 입으니 더 멋진 다섯 남자" ['Music Core' Shinee, five men who look more handsome in uniform]. Asian Economy (in Korean). Archived from the original on June 7, 2021. Retrieved June 7, 2021 – via Naver.
^Kim, Kyung-joo (October 13, 2013). "'컴백' 샤이니, 감미+섹시+카리스마..3색 매력 발산" ['Comeback' Shinee, sweet + sexy + charismatic... tricolor charm]. Osen (in Korean). Archived from the original on June 7, 2021. Retrieved June 7, 2021 – via Naver.
^Lim, Young-jin (October 16, 2013). "샤이니, 태풍 뚫고 무사 귀국.."스케줄 이동 중"" [Shinee returned home safely during typhoon.. 'Schedule is proceeding']. Osen (in Korean). Archived from the original on June 7, 2021. Retrieved June 7, 2021 – via Naver.
^"2013년43주차 Digital Chart" [Digital Chart – Week 43 of 2013]. Gaon Chart (in Korean). Archived from the original on April 24, 2021. Retrieved June 7, 2021.
