A method and apparatus for detecting metal extrusion associated with electromigration (EM) under high current density situations within an EM test line by measuring changes in capacitance associated with metal extrusion that occurs in the vicinity of the charge carrying surfaces of one or more capacitors situated in locations of close physical proximity to anticipated sites of metal extrusion on an EM test line are provided. The capacitance of each of the one or more capacitors is measured prior to and then during or after operation of the EM test line so as to detect capacitance changes indicating metal extrusion.