Blood sugar & metabolism
HbA1c: more than a single-day snapshot
4 min read
What the test measures
HbA1c measures glucose attached to haemoglobin in red blood cells. It gives an indication of average blood glucose over roughly two to three months, with more recent weeks contributing more.
HbA1c and a fasting or random glucose reading measure different things. A report that simply says glucose must not automatically be labelled fasting glucose.
Why a result needs context
Anaemia, some haemoglobin variants, pregnancy, kidney disease and recent blood loss or transfusion can affect how HbA1c should be interpreted. Your doctor may recommend other tests or an individual target.
Lumen does not diagnose diabetes or prediabetes from a percentage, and it does not apply a single country's diagnostic cut-offs to everyone.
Percent and mmol/mol are different units
Reports may express HbA1c as a percentage or in mmol/mol. Lumen preserves the unit shown on the source. Different units are not joined into one trend.
Bring the whole story
Discuss your results with your GP, including medicines, symptoms and your usual eating and activity patterns. Do not adjust diabetes medicine from an app reading. Seek medical help promptly if you are unwell.
Further reading
Educational editorial content, updated 25-Oct-2026. Not a clinician-reviewed assessment. External sources may describe guidance for a particular country. Discuss what applies to you with your clinician.
This article is for general information and education only. It is not medical advice and cannot account for your personal history. Always consult a qualified healthcare professional about your results.