Blood glucose explained — what the numbers mean for diabetes

Blood glucose (blood sugar) is measured in millimoles per litre (mmol/L) in the UK.

Normal and target ranges

• Non-diabetic fasting: 3.5–5.5 mmol/L
• Type 2 diabetes target (fasting): 4–7 mmol/L
• Type 2 diabetes target (2 hours after meals): below 8.5 mmol/L
• These are general targets — your diabetes team will set personalised goals

HbA1c

HbA1c is a 3-month average glucose level, tested by your GP every 3–6 months. A target below 48 mmol/mol (6.5%) indicates well-controlled diabetes. Above 58 mmol/mol (7.5%) suggests adjustment to treatment may be needed.

Hypoglycaemia

A reading below 4 mmol/L is a hypo. Symptoms: shaking, sweating, confusion. Treat immediately with fast-acting sugar (Lucozade, glucose tablets, fruit juice). Contact your GP if hypos are frequent.

Track your readings with our free blood sugar log.