The object of the invention is a bed (10) comprising a frame (12) and a mattress (14) hinged and mounted on the frame, the mattress (14) articulated comprising a relief bust (16) rotatably mounted around a tilting axis (AI), the bed (10) comprising a headboard (20), the inclination axis (AI) of this backrest (16) being mounted in translation along the longitudinal central axis (AL) of the bed base (14), this backrest (16) comprising a sliding panel (24) forming part of the bedding surface (22) of the bed base, this sliding panel being mounted in translation on the along a radial axis (AR) extending perpendicularly to the axis of inclination (AI), the inclination of the backrest (16) relative to the frame (12) being obtained via at least one main link (30) articulated between the backrest (16) and the frame (12), and the actuator (18) being connected to the inclination axis (AI) or to the main link (30) , the bed (10) being ca characterized in that the sliding panel (24) is articulated at the end of the main connecting rod (30) connected to the backrest, and in that at least one auxiliary connecting rod (34,341,342) is articulated between the axis of inclination (AI) of the backrest (16) and a point (36) of the main link (30) distinct from the articulation points (38,40) of this main link respectively with the frame (12) and with the pan sliding (24) of the backrest. L'objet de l'invention est un lit (10) comprenant un châssis (12) et un sommier (14) articulé et monté sur ce châssis, ce sommier (14) articulé comprenant un relève-buste (16) monté mobile en rotation autour d'un axe d'inclinaison (AI), le lit (10) comprenant une tête de lit (20), l'axe d'inclinaison (AI) de ce relève-buste (16) étant monté en translation le long de l'axe central longitudinal (AL) du sommier (14), ce relève-buste (16) comprenant un pan coulissant (24) formant une partie de la surface de couchage (22) du sommier, ce pan coulissant étant monté en translation le long d'un axe radi