An apparatus, method and system wherein the apparatus comprises: a pump comprising an attachment portion configured to enable the pump to be attached to a users skin, wherein the pump is configured to draw analytes from the users body into the apparatus by reducing pressure on the users skin in an area covered by the pump at least one detector configured to detect one or more analytes or combinations of analytes which are drawn into the apparatus the apparatus being arranged to be coupled to a controller to enable the pressure on the users skin to be adjusted.
