Blood and lab tests
What Does HbA1c Mean on a Blood Test?
HbA1c · say it: aych-bee-ay-one-seeAlso written: A1c, hemoglobin A1c, glycated hemoglobin, glycosylated hemoglobin
Short answer
HbA1c shows your average blood sugar over roughly the past two to three months by measuring how much sugar is attached to red blood cells.
What it means
Sugar (glucose) in the blood sticks to hemoglobin, the protein in red blood cells that carries oxygen. The more sugar in the blood over time, the more hemoglobin becomes coated. HbA1c measures the share of hemoglobin that is coated.
Red blood cells live for about three months, so HbA1c reflects a longer-term average rather than your sugar level on the day of the test. You usually do not need to fast for it.
It is used to screen for and diagnose diabetes and prediabetes, and to see how blood sugar control is going over time. Results can be reported as a percentage or in mmol/mol, depending on the country.
Where you may see it
- Diabetes screening and monitoring reports
- Routine health check blood panels
- Pregnancy and pre-surgery assessments in some clinics
📄 How it looks on a report
HbA1c 5.9 % (range printed by lab)
🙅 What it does not mean
- It does not show your blood sugar today or after a particular meal; it is a long-term average.
- It is not accurate for everyone. Anaemia, some inherited hemoglobin variants, recent blood loss or transfusion, and pregnancy can affect it.
- One result is rarely used alone to diagnose diabetes; doctors usually confirm it with a repeat or a different test.
🗒️ Questions to ask your doctor
🧾 Reports where you will see “HbA1c”
Paste or upload the report and every line of it is explained, with personal details removed first.
💊 Medicines whose labels mention “HbA1c”
Plain-English explanations of each medicine, from its official FDA label.
- Ampicillin Sodium
a penicillin-type antibacterial medicine
- Atorvastatin
a statin, a cholesterol-lowering medicine of the HMG-CoA reductase inhibitor type
- Pioglitazone
a diabetes medicine of the thiazolidinedione type
- Rosuvastatin
a cholesterol-lowering medicine of the statin type (an HMG CoA reductase inhibitor)
- Sitagliptin
a DPP-4 inhibitor, a type of medicine used to lower blood sugar in adults with type 2 diabetes
- Trazodone
an antidepressant of the selective serotonin reuptake inhibitor (SSRI) type, which the label also describes as a 5HT2 receptor antagonist
🔗 Read more from trusted sources
- “HbA1c” on MedlinePlus ↗
US National Library of Medicine
- MedlinePlus lab test guides ↗
US National Library of Medicine
Seeing this word on your own report? Get every line of it explained, free.
Explain my report🧩 Related words
🔎 Look up another word
More words: blood and lab tests
General information about a medical word, not advice about your own results. Ask the clinician who ordered the test what it means for you.