What are the key diagnostic criteria for diabetic ketoacidosis (DKA) in adults?

The key diagnostic criteria for diabetic ketoacidosis (DKA) in adults typically involve a triad of findings: hyperglycaemia, ketosis, and metabolic acidosis (Dhatariya et al., 2020; Rodriguez Alvarez et al., 2025). Specifically, DKA is diagnosed in adults based on a plasma glucose level greater than 11 mmol/litre, the presence of ketosis, and acidosis ²,³. Ketosis can be indicated by moderate ketonuria (2+ on urine dipstick) or ketonaemia (1.5–2.9 mmol/L) ²,³. For a definitive diagnosis, blood beta-hydroxybutyrate levels above 3 mmol/litre or significant ketonuria (2+ or more on a standard strip) are indicative of ketosis [1, Dhatariya et al., 2020]. Metabolic acidosis is characterised by a blood pH below 7.3 or plasma bicarbonate below 15 mmol/litre [1, Dhatariya et al., 2020]. While the NICE guideline primarily details DKA in children and young people, the principles of diagnosis, including hyperglycaemia and ketosis, are considered for adults in clinical practice ¹,²,³. Capillary blood ketone testing should be considered in adults with suspected DKA or uncontrolled diabetes with positive urine ketones ⁴.