Invasive urodynamic studies (UDI) are the gold standard of LUTD diagnosis. UDI is done by the treating physician her or himself or by a designated and dedicated other person. A report with a diagnosis is the ultimate aim of UDI. The UDI-report includes information about all relevant events during the tests, technical quality and reliability. The UDI-report includes also all elementsof LUT function measured related to limits of normal. Grading and staging of dysfunction and UDI-patterns are reported in standard terms in combination with the patient’s reporting of representativeness and combined with the patient’s symptoms and perceived signs of dysfunction. Finally a UDI-report concludes with a urodynamic diagnosis in standard terms.