What Is HbA1c and Why Does It Matter?

What Is HbA1c and Why Does It Matter?

If you have ever had blood work done to check for diabetes or prediabetes, you may have seen something called HbA1c. It sounds technical, but the idea behind it is actually simple and very useful. HbA1c gives doctors and patients a way to understand blood sugar patterns over time rather than relying on a single snapshot.

HbA1c stands for hemoglobin A1c. Hemoglobin is a protein found in red blood cells that carries oxygen throughout the body. When glucose circulates in the bloodstream, some of it naturally attaches to hemoglobin in a process called glycation. The HbA1c test measures how much of that hemoglobin has glucose attached to it.

What makes HbA1c especially valuable is that it reflects average blood sugar levels over the previous two to three months. Red blood cells live for about 120 days, so the amount of glucose attached to hemoglobin depends on how much sugar has been present in the blood during that time. This means HbA1c is not affected much by what you ate yesterday or whether you were stressed the morning of the test.