HbA1c Test: Do You Need to Fast? Normal Values (range) and Targets

Do you need fasting for HbA1c?

No, HbA1c can be done at any time of the day, fasting or non-fasting.

It is different from fasting and post-meal sugars because HbA1c reflects your overall average glucose over the past few months, not your sugar at that exact moment.

Why HbA1c is called a “3-month average”

HbA1c measures how much glucose has attached to hemoglobin inside your red blood cells.

Red blood cells normally live for about 120 days. So HbA1c acts like a “report card” of glucose exposure over the last 2-3 months, with more weightage to recent weeks.

HbA1c cutoffs

These are widely used cutoffs:

• Normal: Below 5.7%.
• Prediabetes: 5.7% to 6.4%.
• Diabetes: 6.5% or higher.
  (Your doctor may repeat the test or confirm with another test depending on symptoms and situation.)

What HbA1c target should you aim for?

There is no single “perfect” target for everyone. Targets are individualized.

Common practical targets used in clinic:

• Most non-pregnant adults with type 2 diabetes: Often aim around <7% if it can be achieved safely
• If you are older, have heart disease, kidney disease, frequent low sugars, or multiple medications: Doctors may keep the target a bit higher (more relaxed) to reduce hypoglycaemia risk.
• If you are young, newly diagnosed, and low hypoglycaemia risk: Doctors may aim tighter.

Important points patients should remember

• HbA1c does not replace fasting and post-meal sugars. All three together give the best picture.
• HbA1c can be misleading in some situations. In such cases, your doctor may rely more on SMBG/CGM or other lab methods.
• Do not change medicines based only on one value. Use HbA1c as a trend, plus your glucose readings.

Simple takeaway

• HbA1c does NOT require fasting.
• It reflects average glucose over ~2-3 months.
• Cutoffs help diagnose diabetes, but targets must be personalized, especially if hypoglycaemia risk is present.

Disclaimer: This is general education. Please discuss your HbA1c goal and medication changes with your physician/endocrinologist, because targets vary by age, comorbidities, pregnancy status, and hypoglycaemia risk.