What Is Hemoglobin A1c (HbA1c)
Hemoglobin A1c (HbA1c) is a blood marker that reflects your average blood glucose level over the past two to three months. Also called A1c or glycated hemoglobin, it measures the percentage of hemoglobin — the oxygen-carrying protein in red blood cells — with glucose attached to it.
Hemoglobin A1C reflects average blood glucose over approximately three months. This makes HbA1c different from fasting glucose, which measures blood sugar at a single point in time. Hone physicians assess both markers to get a more complete picture of how well your body regulates blood sugar and your overall metabolic health.
Why Does HbA1c Matter?
- Helps detect prediabetes and type 2 diabetes. Hemoglobin A1C levels might be high and indicate prediabetes even when fasting glucose levels appear normal. 1
- Helps assess heart disease risk. Persistently high hemoglobin A1C contributes to glycation, oxidative stress, and blood vessel dysfunction. Over time, these changes can promote atherosclerosis and increase the risk of heart disease, stroke, and heart failure.2
- Tracks whether interventions are improving metabolic risk. Repeat HbA1c blood tests show whether nutrition, exercise, weight management, and medical treatment are lowering average blood glucose.
Book your test now
Test 50+ biomarkers & meet with a longevity physician, uncover the root cause of symptoms
- HSA/FSA eligible
- Physician reviewed
- 100% satisfaction guaranteed
How to Interpret HbA1c Levels
Levels of 5.7–6.4% indicate prediabetes; levels of 6.5% or above indicate diabetes.
(Ranges may vary slightly by lab)
Standard reference ranges represent the middle 95% of healthy individuals but don’t necessarily reflect levels associated with longevity. Optimal ranges are derived from clinical guidelines, peer-reviewed research, and real-world outcomes data, with an emphasis on levels associated with peak functioning and reduced disease risk.
Benefits of Optimizing HbA1c
- Lower risk of heart attack and stroke
- Lower risk of diabetes
- More stable energy and fewer blood sugar swings throughout the day
- Lower dementia risk3
- Reduced risk of chronic kidney disease
- Healthier blood vessels and circulation
Know your numbers. Own your health.
50+ biomarkers that reflect how your body is functioning — and where there’s room to optimize. Plus a clinical consult and personalized treatment plan. All for $65.
Low HbA1c Levels
HbA1c levels below 5.7% generally mean your blood sugar has stayed within a healthy range over the past few months. Very low HbA1c levels, however, can occasionally occur with certain forms of anemia or other medical conditions and should be interpreted in the context of your overall health.
High HbA1c Levels
A high HbA1c means average blood glucose has been elevated over the past two to three months. A result of 5.7–6.4% hemoglobin A1C falls within the prediabetes range. A result of 6.5% hemoglobin A1C or higher meets the diabetes threshold.
Symptoms:
Many people have no symptoms until blood glucose has been elevated for years, making routine laboratory testing one of the best ways to detect metabolic disease early. When blood glucose becomes more significantly or persistently elevated beyond its normal range, symptoms may include:
- Increased thirst and frequent urination
- Increased hunger
- Fatigue and low energy, especially after meals
- Blurred vision
- Slow wound healing
- Recurrent infections
- Tingling or numbness in hands or feet
Causes:
- Insulin resistance driven by excess body fat, particularly visceral fat
- Sedentary lifestyle and low muscle mass
- Diet high in refined carbohydrates, added sugars, and ultra-processed foods
- Chronic poor sleep or sleep apnea
- Chronic psychological stress
- Genetic predisposition to insulin resistance or impaired insulin secretion
- Polyendocrine Metabolic Ovarian Syndrome (PMOS) in women. formerly called Polycystic ovary syndrome (PCOS)
- Metabolic dysfunction-associated steatotic liver disease (MASLD) formerly called non-alcoholic fatty liver disease (NAFLD)
Healthspan Impacts:
- Higher coronary heart disease and stroke risk, even in people without a diabetes diagnosis
- Accelerated biological aging
- Increased risk of heart failure and cardiovascular mortality
- Progressive damage to the kidneys, eyes, and peripheral nerves through microvascular injury
- Increased risk of cognitive decline and dementia
How Hone Treats Out of Range HbA1c Levels
Your Hone physician evaluates HbA1c levels from a blood test alongside fasting glucose, fasting insulin, triglycerides, HDL cholesterol, and other metabolic markers to assess glycemic health and guide treatment.
Selvin E, et al. (2010). Glycated hemoglobin, diabetes, and cardiovascular risk in nondiabetic adults.
↑Selvin E, et al (2005). Glycemic control and coronary heart disease risk in persons with and without diabetes: the atherosclerosis risk in communities study.
↑Crane PK, et al. (2013). Glucose levels and risk of dementia.
↑Guo J, et al. (2021). The effect of berberine on metabolic profiles in type 2 diabetic patients: a systematic review and meta-analysis of randomized controlled trials.
↑Veronese N, et al. (2016). Effect of magnesium supplementation on glucose metabolism in people with or at risk of diabetes: a systematic review and meta-analysis.
↑
Reviewed for Accuracy by Our Medical Review Board
This biomarker information has been reviewed by a member of Hone’s medical review board. As part of the medical review team, physicians fact-check this content against the latest research and their own experience treating their patients.
Ashley Winter, M.D., is a board-certified urogynecologist trained at Weill Cornell and Cleveland Clinic. She specializes in female and male sexual dysfunction, urinary issues, genital pain, and hormone therapy.
James Staheli, D.O., is the Medical Director for Broad Health, Hone Health’s affiliated medical practice and a family medicine doctor in Atlanta, Georgia.
