What Is the A1C Blood Test for Diabetes?

A1C blood test measures the amount of sugar (glucose) attached to hemoglobin, a protein in red blood cells.

- Red blood cells typically live four months.

- A high A1C level means blood glucose levels have been too high for several months.

- Normal A1C is 4% to 5.6%.

A1C blood test measures three months' worth of average blood sugar levels. People who are at risk for diabetes or have diabetes should have an A1C test:

- Everyone with diabetes

- People with prediabetes

- Pregnant people with gestational diabetes

- Women with a history of gestational diabetes

- Adults with high blood pressure

- People with high blood sugar levels (over 140 mg/dL when fasting or 200 mg/dL at other times)

- Obese people

- People with physical inactivity

- People with first-degree relatives with diabetes

- Certain minority groups, including African, Hispanic, Asian, and American Indian groups

- People with conditions like cancer, kidney disease, or HIV that increase diabetes risk

How can you lower your A1C levels?

- Lose weight and exercise regularly

- Eat a healthy diet

- Take medications to lower blood sugar as needed

- Work with the medical care team to manage diabetes