HbA1c or fasting blood sugar: which test do you need?

World Diabetes Day falls on 14 November. The theme for 2026, set by the International Diabetes Federation and the WHO, is Early action on diabetes, with a focus on earlier diagnosis. Two blood tests are used most often to check blood sugar: fasting blood sugar (FBS) and HbA1c. They measure different things, and your doctor may ask for one or both.

Fasting blood sugar (FBS)

FBS measures the glucose in your blood at the moment the sample is taken, after an overnight fast. You should have nothing but water for at least 8 hours before the test, so it is usually booked as an early-morning collection.

HbA1c

HbA1c reflects your average blood sugar over roughly the past two to three months. It does not require fasting and can be collected at any time of day. Because it reflects a longer period, a single meal has little effect on the result.

The ranges doctors use

The American Diabetes Association's Standards of Care in Diabetes 2026 use these ranges for adults:

• HbA1c: below 5.7% is in the normal range; 5.7% to 6.4% is the prediabetes range; 6.5% or above is in the diabetes range.
• Fasting plasma glucose: below 100 mg/dL is in the normal range; 100 to 125 mg/dL is the prediabetes range; 126 mg/dL or above is in the diabetes range.

A single result is usually confirmed with a repeat test before any diagnosis. Your doctor decides what your result means for you.

When HbA1c may not be the right test

Conditions that affect red blood cells, such as some forms of anaemia, recent blood loss or a transfusion, and pregnancy, can affect HbA1c. If any of these apply, tell your doctor, who may prefer a glucose test.

Who is usually advised to test

The ADA 2026 Standards recommend screening for all adults from age 35, and earlier for people with additional risk factors. Your doctor can advise how often you should test.

Booking at Neulife Labs

Fasting Blood Sugar (FBS) is ₹60 and HbA1c is ₹470. Both can be collected in a single home visit; book a morning slot if FBS is included. Discuss your report with your doctor.

Sources: American Diabetes Association, Standards of Care in Diabetes 2026, Section 2: Diagnosis and Classification of Diabetes. World Health Organization and International Diabetes Federation, World Diabetes Day 2026: Early action on diabetes.