What criteria should I use to determine if a patient with hyperglycaemia requires referral to a specialist?

Criteria for referral of a patient with hyperglycaemia to a specialist include:

• HbA1c level of 48 mmol/mol (6.5%) or above indicating type 2 diabetes, warranting referral for further care NICE NG3.
• Suspected or confirmed type 1 diabetes, especially in adults presenting with ketosis, rapid weight loss, age under 50 years, BMI below 25 kg/m2, or autoimmune history, requiring specialist diagnosis and management NICE NG17.
• Children and young people with suspected type 1 diabetes should be referred immediately (same day) to a multidisciplinary paediatric diabetes team NICE NG18.
• Presence of hyperglycaemic emergencies such as diabetic ketoacidosis (DKA) or hyperosmolar hyperglycaemic state (HHS), or moderate ketonuria/ketonaemia with inability to eat or drink, necessitating emergency hospital admission or specialist advice NICE CKS.
• Unclear underlying condition causing hyperglycaemia, dehydration or risk of dehydration, persistent vomiting beyond 2 hours, or failure to improve with insulin treatment in insulin-treated patients, indicating need for specialist input or hospital admission NICE CKS.
• Suspected acute kidney injury that cannot be managed in primary care requires specialist referral NICE CKS.
• If insulin titration or adjustment is required, this should be done by a healthcare professional with relevant expertise and training NICE CKS,NICE CKS,NICE CKS.

Summary: Referral to a specialist is indicated for confirmed diabetes diagnosis at diagnostic thresholds, suspected type 1 diabetes, hyperglycaemic emergencies, unclear or complicated clinical presentations, and when specialist insulin management is needed NICE NG3,NICE NG17,NICE NG18,NICE CKS,NICE CKS,NICE CKS,NICE CKS.