A blood test that estimates your average blood sugar over the past two to three months, reported as a percentage. It's the main number used to diagnose and track type 2 diabetes and prediabetes — broadly, 5.7–6.4% is prediabetes and 6.5% or higher is diabetes. GLP-1 medications often lower A1c, which is why prior-authorization letters for diabetes coverage usually require a recent value.
Related terms: Type 2 diabetes · Prediabetes · Insulin resistance
See also: PA letter templates