What factors can cause diabetes mellitus? In type 1 diabetes, the exact causes are often of unknown origin, although there are factors that give rise to this typology, such as genetic inheritance and the immune factor (antibodies destroy the cells that produce insulin). The factors that are most often associated with the development of type 2 diabetes mellitus are an overweight and sedentary lifestyle. Blood Sugar Ultra Nz. That Is, a Lifestyle with Little Physical Activity and a diet in which an excess of saturated fats and simple sugars is ingested can favor the development of type 2 diabetes. What symptoms do you have and when does it usually manifest? Type 1 diabetes usually develops before age 30 and the symptoms are very striking, because the lack of insulin usually appears abruptly with signs of very altered glycemia: very thirsty, need to urinate very frequently and a significant loss of weight. Type 2 Diabetes However usually develops progressively and the patient has no clear symptoms (similar to those of type 1 diabetes) until the disease is more developed and sugar levels are really very high, because what is very difficult to find early an alteration that can be assigned to type 2 diabetes.