A multi-segment intraluminal guide wire (100, 200, 300, 400) comprising: an elongate first distal portion (104, 204, 304, 404) comprising a first metallic material; an elongate second proximal portion (102, 202, 302, 402) comprising a second metallic material that is different from the first metallic material, the distal and proximal elongate portions (104, 102; 204, 202; 304, 302; 404; 402) being joined together end to end by a solid-state weld joint (103, 203, 303, 403); a diameter of a weld region surrounding the weld joint (103, 203, 303, 403) being reduced relative to a diameter of the distal and proximal portions (104, 102; 204, 202; 304, 302; 404, 402) of the guide wire (100, 200, 300, 400) on either side of the weld region; and a stiffness adjusting sleeve (105, 205, 305, 405) disposed over the weld joint (103, 203, 303, 403) so that a transition profile of bending stiffness across the weld region is gradual rather than abrupt across the distal portion of the guide wire (104, 204, 304, 404) to the proximal portion of the guide wire (102, 202, 302, 402), characterised in that the stiffness adjusting sleeve (105, 205, 305, 405): is formed from a multifilar coil including multiple strands of helically wound wire disposed over the weld region so that a transition profile of bending stiffness across the weld region is gradual rather than abrupt across the distal portion of the guide wire (104, 204, 304, 404) to the proximal portion of the guide wire (102, 202, 302, 402); or includes a sleeve body in which at least one end thereof is tapered in thickness so that a transition profile of bending stiffness across the weld region is gradual rather than abrupt across the distal portion of the guide wire (104, 204, 304, 404) to the proximal portion of the guide wire (102, 202, 302, 402). an elongate first distal portion (104, 204, 304, 404) comprising a first metallic material; an elongate second proximal portion (102, 202, 302, 402) comprising a second metallic material that is different from the first metallic material, the distal and proximal elongate portions (104, 102; 204, 202; 304, 302; 404; 402) being joined together end to end by a solid-state weld joint (103, 203, 303, 403); a diameter of a weld region surrounding the weld joint (103, 203, 303, 403) being reduced relative to a diameter of the distal and proximal portions (104, 102; 204, 202; 304, 302; 404, 402) of the guide wire (100, 200, 300, 400) on either side of the weld region; and a stiffness adjusting sleeve (105, 205, 305, 405) disposed over the weld joint (103, 203, 303, 403) so that a transition profile of bending stiffness across the weld region is gradual rather than abrupt across the distal portion of the guide wire (104, 204, 304, 404) to the proximal portion of the guide wire (102, 202, 302, 402), characterised in that the stiffness adjusting sleeve (105, 205, 305, 405): is formed from a multifilar coil including multiple strands of helically wound wire disposed over the weld region so that a transition profile of bending stiffness across the weld region is gradual rather than abrupt across the distal portion of the guide wire (104, 204, 304, 404) to the proximal portion of the guide wire (102, 202, 302, 402); or includes a sleeve body in which at least one end thereof is tapered in thickness so that a transition profile of bending stiffness across the weld region is gradual rather than abrupt across the distal portion of the guide wire (104, 204, 304, 404) to the proximal portion of the guide wire (102, 202, 302, 402). is formed from a multifilar coil including multiple strands of helically wound wire disposed over the weld region so that a transition profile of bending stiffness across the weld region is gradual rather than abrupt across the distal portion of the guide wire (104, 204, 304, 404) to the proximal portion of the guide wire (102, 202, 302, 402); or includes a sleeve body in which at least one end thereof is tapered in thickness so that a transition profile of bending stiffness across the weld region is gradual rather than abrupt across the distal portion of the guide wire (104, 204, 304, 404) to the proximal portion of the guide wire (102, 202, 302, 402).