Diabetes is not a contagious disease and is not transmitted by any means. Diabetes mellitus is a group of metabolic diseases characterized by chronic hyperglycemia caused by a variety of etiological factors, mainly due to defects in insulin secretion and/or utilization. Causes of diabetes mellitus include genetic environmental factors, infectious factors, chemical immune factors, and poor lifestyle. Infectious diseases are a group of diseases caused by a variety of pathogens that can be transmitted from person to person and from animal to person. Pathogens can be viruses (e.g. influenza virus, new coronavirus), parasites (Schistosoma haematobium), bacteria (dysentery bacillus) and so on. The means of transmission include airborne, waterborne, and foodborne. Therefore, diabetes is not an infectious disease and does not have the characteristics of an infectious disease and is not transmitted by any means. If a patient develops diabetes, it is recommended that he or she seeks medical attention and standardized treatment.