Ketoacidosis is a severe metabolic complication of diabetes mellitus that occurs mainly in type 1 diabetes, although it is not unusual even for some patients with type 2 diabetes. Ketoacidosis may represent the onset manifestation of type 1 diabetes, a situation in which the patient's condition is serious and requires prompt diagnosis and sustained treatment. We present the case of a patient with severe ketoacidosis as a primary manifestation of type 1 diabetes, in whom the integration of clinical, biochemical and functional data and their interpretation in the context of the pathophysiological events, and also a specific application of treatment guidelines led to a favorable clinical outcome. [ABSTRACT FROM AUTHOR]