Diabetes is an increasingly common diagnosis in the population regardless of age. The most common forms are type 1 diabetes (T1DM) and type 2 diabetes (T2DM) along with other subtypes of the disease. Non-adherence and untimely response to patients' own symptoms can lead to acute complications including diabetic ketoacidosis, hypoglycemia and non-ketotic hyperosmolar syndrome whose pathophysiology, clinical picture, diagnosis, treatment and complications will be described in detail in the paper. These are all medical emergencies that can be fatal. Acute complications occur due to uncontrolled elevated blood sugar (hyperglycemia) and low blood sugar (hypoglycemia) caused by a mismatch between available insulin and needs. Serious life-threatening complications can occur quickly. But such complications can pass just as quickly with the education of the patient and his loved ones. The American Diabetes Association (ADA) recently announced its 2021 medical care standards, which provide healthcare professionals, researchers, and insurers with updated guidelines on diabetes care and management. These recommendations have been developed by a team of experts building on previous Standards reviewing the latest and most significant scientific research. There is significant evidence to support interventions to improve diabetes outcomes. Maintaining blood sugar, taking medications, controlling blood pressure and blood fats can greatly reduce the risk of developing complications. That means going to diabetes checkups and being taught by the diabetes health team how to take care of themselves between appointments. The biggest role lies with the patient. The quality of care lies in the cooperation of the medical team, which includes a specialist, a nurse and a dietitian. Nurses have an important role to play in educating patients and following physician instructions so that acute complications do not recur or, at best, do not occur at all. In the care of such patients, the nurse must be acquainted with the history of the disease, current physical condition, laboratory findings in order to be able to make a detailed and quality health care plan to manage the disease and educate the patient about prevention. Data for this paper were collected in professional articles, books and portals from the period from 2000 to 2021.