“…After a transitory phase in which visceral pain is perceived as a direct symptom, in fact, (the so-called "true visceral pain," always felt along the midline, whatever the viscus in question, accompanied by marked neurovegetative signs and emotional reactions), the sensation is "transferred" (and called übertragener Schmerz, ie, transferred pain, by the German authors) to somatic areas of the body wall, which differ according to the specific viscus and which are generally located within the relative metameric field [17,33,34]. In these areas, a condition of secondary hyperalgesia most often arises, especially if the algogenic condition of the internal organ reoccurs frequently or is prolonged; this may involve all three somatic tissues of the body wallskin, subcutis, and muscle-but is most often localized at the muscle level (referred muscle pain with and without hyperalgesia) [4,35•].…”