The invention relates to a rotor (10) for a turbo machine, in particular for an aircraft turbine, having rotating blades (12), which are joined with a basic rotor body (16) and, radially underneath their blade platforms (18), comprise channels (22) for introducing cooling air (KL) into rotating blades (12), whereby a gas diffusor (24) is provided on a high-pressure (HD) side of rotor (10), this diffusor being designed to at least reduce a hot-gas (HL) flow into channels (22) during the operation of the associated turbo machine and to permit an entry of cooling air (KL) into channels (22), whereby gas diffusor (24) is joined to rotor (10) and comprises a blocking element (28) running annularly in the circumferential direction of rotor (10). A related method for manufacturing, repairing and/or overhauling a rotor (10) for a turbo machine is also provided.