What does A1C measure?

A1C (also called HbA1c or glycated hemoglobin) measures your average blood sugar over the past 2-3 months. It shows what percentage of your hemoglobin proteins have sugar attached to them.

How often should I test my A1C?

Most people with diabetes should test A1C every 3 months. If your diabetes is well-controlled, your doctor may recommend testing every 6 months. Those with prediabetes typically test once a year.

What is a good A1C target?

For most adults with diabetes, the target is below 7%. However, targets vary by age, health conditions, and hypoglycemia risk. Older adults or those with complications may have higher targets (7.5-8%). Discuss your personal target with your doctor.

Yes. A1C can be lowered through diet changes, exercise, weight loss, and medications. Most people see changes within 2-3 months. A 1% reduction in A1C significantly reduces complication risk.

Why is my A1C different from my home glucose readings?

Home glucose shows a single moment in time, while A1C reflects a 3-month average. Post-meal spikes you might miss with occasional testing still affect A1C. Tracking both gives a complete picture.

LabLi Sign In

Diabetes Lab Guide

Understanding Your A1C Results

A1C is the most important number for diabetes management. Learn what your result means and how to improve it.

What is A1C?

A1C (also called HbA1c or hemoglobin A1c) is a blood test that measures your average blood sugar over the past 2-3 months.

Here's how it works: Sugar in your blood attaches to hemoglobin, a protein in red blood cells. The more sugar in your blood, the more gets attached. Since red blood cells live about 3 months, A1C shows your average blood sugar during that time.

Unlike a finger-prick glucose test that shows your blood sugar at one moment, A1C gives you the big picture — it reveals how well your blood sugar has been controlled overall, including the highs and lows you might miss with occasional testing.

Example: An A1C of 7% means about 7% of your hemoglobin has sugar attached, which corresponds to an average blood sugar of ~154 mg/dL over 3 months.

Below 5.7%Normal

Healthy blood sugar control

5.7% – 6.4%Prediabetes

Increased risk, reversible with lifestyle changes

6.5% and aboveDiabetes

Diabetes diagnosis, requires management

What Does Your A1C Mean?

Select your A1C value for a detailed explanation of what it means and what to do next.

5.7%

Prediabetes threshold

Why A1C Matters

A1C gives you the big picture of your blood sugar control. While daily glucose readings show individual moments, A1C reveals your average over 2-3 months.

Predicts Complications

Each 1% drop reduces risk of eye, kidney, and nerve damage by 25-40%

Tracks Progress

Shows if your diet, exercise, or medications are working

Catches Hidden Spikes

Reveals post-meal highs you might miss with occasional testing

Guides Treatment

Helps your doctor adjust medications and set goals

A1C to Average Glucose Conversion

A1C	Avg Glucose (mg/dL)	Avg Glucose (mmol/L)
5.7%	117	6.5
6.0%	126	7.0
6.5%	140	7.8
7.0%	154	8.6
8.0%	183	10.2
9.0%	212	11.8
10.0%	240	13.4

Formula: Average glucose (mg/dL) = (A1C × 28.7) - 46.7

What Can Affect Your A1C

Several factors influence your A1C beyond just diet. Understanding these helps you interpret your results accurately.

Diet & Carbohydrates

High-carb meals cause blood sugar spikes. Refined carbs (white bread, sugary drinks) have a bigger impact than whole grains and fiber-rich foods.

Physical Activity

Exercise helps your cells use glucose more efficiently. Both aerobic activity and strength training can lower A1C over time.

Medications

Diabetes medications directly lower A1C. Some other drugs (steroids, certain antipsychotics) can raise blood sugar.

Weight Changes

Losing 5-10% of body weight can significantly improve A1C. Even modest weight loss helps your body use insulin better.

Stress & Sleep

Chronic stress raises cortisol, which increases blood sugar. Poor sleep (less than 6 hours) affects insulin sensitivity.

Illness & Infection

Being sick temporarily raises blood sugar as your body fights infection. This can affect A1C readings if illness was prolonged.

How to Lower A1C Safely

Sustainable changes work better than extreme measures. Most people can lower A1C by 1-2% over 3 months with consistent effort.

Reduce refined carbs gradually

Swap white rice for brown, sugary drinks for water. Don't eliminate all carbs — your body needs them.

Walk after meals

Even a 10-15 minute walk after eating helps your muscles absorb glucose and prevents post-meal spikes.

Prioritize sleep

Aim for 7-8 hours per night. Poor sleep increases insulin resistance and hunger hormones.

Build muscle

Muscle tissue uses glucose for energy. Strength training 2-3 times per week improves long-term blood sugar control.

Take medications as prescribed

If your doctor prescribes metformin or other medications, consistent use is essential. Don't adjust doses on your own.

Important: Lowering A1C too fast (more than 2% in 3 months) can sometimes cause complications in people with long-standing high A1C. Work with your doctor to set a safe pace.

Why Tracking A1C Over Time Matters

A single A1C reading tells you where you are. Multiple readings over time tell you where you're heading.

Your A1C trend reveals whether your lifestyle changes and treatments are actually working. A slow, steady downward trend is more meaningful than any single number. Conversely, a creeping upward trend signals it's time to adjust your approach before problems develop.

Rising Trend

Time to reassess diet, exercise, or medication

Stable Trend

Current approach is maintaining control

Declining Trend

Changes are working — keep it up

Track Your A1C Over Time

Upload your lab reports and see your A1C trend. Know if your treatment is working.

Start Tracking Free

Blood Glucose Guide Diabetes Biomarker Guide A1C Test Reference Home Glucose Tracking