'Yancin lafiya shine haƙƙin tattalin arziki, zamantakewar al'umma, da al'adu don mafi ƙarancin ƙimar kiwon lafiya wanda kowa ke da haƙƙi. An tsara ma'anar haƙƙin lafiya a cikin yarjejeniyoyin ƙasa da ƙasa waɗanda suka haɗa da Sanarwar Duniya game da 'Yancin Dan Adam, Yarjejeniyar tattalin arziƙi, tattalin arziki da al'adu, da yarjejeniyar kan Hakkokin Nakasassu. Akwai muhawara kan fassara da aiki da haƙƙin kiwon lafiya saboda la'akari kamar yadda aka ayyana lafiya, waɗanne ƙananan haƙƙoƙi ke ƙunshe cikin haƙƙin lafiya, da kuma waɗanne cibiyoyi ke da alhakin tabbatar da haƙƙin kiwon lafiya. Gabatarwar tsarin mulki na hukumar lafiya ta duniya ta 1946 (WHO) ta ayyana kiwon lafiya a matsayin "yanayi na cikakkiyar lafiyar jiki, ta tunani da zamantakewarmu ba kawai rashin cuta ko rashin lafiya ba." Kundin tsarin mulki ya ayyana 'yancin kiwon lafiya a matsayin "jin dadin mafi girman matsayin kiwon lafiya," kuma ya fitar da wasu ka'idoji na wannan' yancin a matsayin ci gaban yaro mai lafiya; daidaita yaddar ilimin likitanci da fa'idodin sa; da matakan zamantakewar da gwamnati ta bayar don tabbatar da isasshen lafiya.