Diabetes mellitus is a metabolic disorder of multiple etiology and is characterized by a state of chronic hyperglycemia with disturbed carbohydrate, fat and protein metabolism due to impaired insulin secretion and/or impaired insulin action. According to estimates by the International Diabetes Federation, in 2021, 537 million adults aged 20-79 in the world were living with a diagnosis of diabetes. According to data from the CroDiab Register of people with diabetes, there were 303,992 people with diabetes in Croatia in 2018. Earlier research showed that only 60% of sick people in Croatia have a diagnosis, and the estimate of the total number of sick people is around 500,000. In 2017, diabetes was the 4th leading cause of death with a share of 4.4%.It is not only the current large number of people with diabetes that is worrying, but also the marked increase in the frequency of diabetes during the last decades, which continues continuously, so diabetes is often referred to as a global epidemic. Chronic complications of dibetes mellitus are the main cause of mortality and morbidity of people with diabetes mellitus and significantly impair their quality of life. In synergy with cardiomyopathy, the diagnosis and treatment of such patients becomes even more complex, therefore an individual approach is necessary. When including sick patients in the health care process, the most important thing is to support the patient to accept his health condition and gain a trusting relationship in order to make it easier for him to take care of himself at home.