The authors agree in noting the Sicilian origin of the surname and its probable link with the Arabic term haggam (also transcribed as hağğām), which designated the applier of leeches, the barber and the surgeon. V. Blunda specifies that it is a surname of occupational base, and recalls that in the medieval medical tradition that trade combined the cutting of hair, minor surgery and therapeutic bloodletting.

F. Miranda considers it a variant of the surname Gangemi, both arisen from the Italianisation of that same Arabic etymon, and adds that it could also derive from an alteration of the Latin surname Cangemius. E. Rossoni broadens this second hypothesis by noting that the surname could come from the name of a locality, such as the Contrada Cangemi of Termini Imerese, in the Palermo area, and documents the use of the surname in Latinised form —Cangemius— as early as the 16th century with the physician Franciscus Cangemius. Rossoni also records a Galterius Changemi in Palermo in 1283 and a Natale Cangemi as parish priest in Alessandria della Rocca in 1593.

Miranda notes that the surname is concentrated in Sicily and is present in the Messina, Palermo, Trapani and Catania areas, with ramifications in other regions of Italy as a result of migratory flows.