Investigating the Safety and Effectiveness of Insulin Degludec in a Real World Population With Type 1 and 2 Diabetes Mellitus

Inclusion Criteria: * Informed consent obtained before any study-related activities (Study-related activities are any procedure related to recording of data according to the protocol) * Male or female patients at least 18 years of age at time of informed consent * T1DM (diagnosed clinically) prior to inclusion in the study, and/or T2DM, insulin using patients (diagnosed clinically) prior to inclusion in the study * Planned initiation with Tresiba® Exclusion Criteria: * Known or suspected hypersensitivity to Tresiba® or any of the excipients listed in Section 6.1 of the SmPC (Summary of Product Characteristics) or related products * Previous participation in this study (i.e. provision of informed consent) * Patients who have previously been treated with Tresiba® * Mental incapacity, unwillingness or language barriers precluding adequate understanding or cooperation