guidelines

type 1 diabetes (adults)

nice ng17: diagnosis + dka safety, basal–bolus principles, targets, hypoglycaemia rules, ketone advice, and annual screening checklist.

last reviewed: 2026-02-13
based on: NICE NG17 (published 26 Aug 2015; last updated 17 Aug 2022; last reviewed 30 Jan 2026)

Immediate safety (don’t miss DKA)

  • Suspect T1DM: polyuria, polydipsia, weight loss, rapid onset symptoms (any age), ketonuria.
  • Urgent same-day if: vomiting, abdominal pain, drowsiness, dehydration, Kussmaul breathing, or raised ketones → possible DKA.
  • At diagnosis: check capillary glucose + ketones, U&Es; involve diabetes team urgently (same day where possible).

Targets + patient safety rules

  • HbA1c: aim ~48 mmol/mol (6.5%) if achievable without problematic hypos; individualise.
  • Hypoglycaemia: 15–20 g fast-acting carbohydrate → recheck in 10–15 min → repeat if needed; follow with longer-acting carbohydrate once recovered.
  • Ketones/sick-day: check ketones with illness, persistent hyperglycaemia, or if unwell. Rising ketones + vomiting = urgent same-day assessment.

Annual review checklist (GP can add real value)

  • Kidney: ACR + eGFR. Eyes: retinopathy screening. Feet: neuropathy/pulses/ulcer risk.
  • CV risk: BP, lipids, smoking, weight; optimise risk reduction with diabetes team alignment.
  • Psychosocial + driving: diabetes distress, hypo awareness, work/driving advice.

Frequently asked questions

Can HbA1c be normal early in T1DM?
Yes. HbA1c is a 2–3 month average; rapid-onset disease can present before it rises substantially—treat the clinical picture.

Transparency

This page is an educational, clinician-written summary of publicly available NICE guidance intended for trained healthcare professionals. It uses original wording (not copied text) and should be used alongside the full NICE source, local pathways, and clinical judgement. Doses provided are for general reference; always check the BNF/SPC.