Diabetes & Stoffwechsel
The HbA1c value indicates the average blood sugar level over several weeks. It helps in the early detection of diabetes and in assessing the progression of a known condition.
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✨ Key Information at a Glance
HbA1c is the "blood sugar memory": The value shows the average blood sugar level of the past weeks to about two to three months.
Below 5.7% is considered normal in the context of diabetes diagnostics; 5.7–6.4% means an increased risk of diabetes; from 6.5% is the diagnostic threshold for diabetes.
An abnormal HbA1c value should not be assessed in isolation.
Certain diseases or changes in red blood cells can distort the HbA1c value.
In cases of known diabetes, the personal HbA1c target value is individually determined.
What is HbA1c?
HbA1c is formed when glucose binds to the red blood pigment hemoglobin. Since red blood cells circulate for several months, the value reflects the blood sugar situation over the past weeks – hence the terms "long-term blood sugar" or "blood sugar memory".
Why is HbA1c alone not sufficient?
HbA1c, fasting blood sugar, and the oral glucose tolerance test assess different aspects of metabolism and can deviate from one another. In the event of contradictory findings, an additional examination may be appropriate.
When can HbA1c be misleading?
The value should always be evaluated in conjunction with the complete blood count and medical history. Factors that can influence it include, among others:
certain forms of anemia
blood loss or a recent transfusion
altered degradation of red blood cells as well as certain hemoglobin variants
severe kidney or liver diseases
pregnancy
In such situations, direct glucose measurements are often more informative.
In cases of diagnosed diabetes
The personal target HbA1c value is determined individually – depending on, among other things, age, comorbidities, and the risk of hypoglycemia. Diagnostic thresholds are not automatically personal therapeutic targets.
🧭 What are the next steps?
1
Understand medical report
2
assess personal risk
3
establish individual goals
4
Monitor progress
5
if necessary, plan therapy together
👵 In advanced age
Treatment goals and therapies are individually tailored to your personal situation.
Concomitant diseases
Medications
Mobility
Memory / Cognition
Self-employment (Selbstständigkeit)
Therapeutic safety
Therefore, in older age, different treatment goals may be appropriate than for younger individuals.
Source: Austrian Diabetes Society — Geriatric Aspects of Diabetes Mellitus (2026 Update)
Children & Adolescents
For the diagnosis of diabetes, the same threshold values generally apply as for adults.
However, clarification, care, and therapy must be carried out in an age-appropriate and family-friendly manner.
In the case of abnormal values, a pediatric or pediatric-diabetological evaluation is recommended.
Source: Austrian Diabetes Association (Österreichische Diabetes Gesellschaft) — Diabetes Mellitus in Childhood and Adolescence (Update 2026)
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⚠️ When should I consult a General Practitioner?
Please have this medically clarified if:
HbA1c levels are repeatedly elevated,
HbA1c and measured blood sugar levels do not match,
symptoms such as severe thirst, frequent urination, unexplained weight loss, or pronounced fatigue occur,
you are pregnant,
medical conditions are present that may affect the HbA1c.
A single laboratory value does not replace a comprehensive medical assessment.
💡 Take-home Message
The HbA1c level indicates your blood sugar control over the past few weeks. However, it is not only the value itself that is crucial, but what it means in your individual personal situation.
Medically reviewed by
Dr. med. Shahzada Amir, M.Sc., Ph.D.
Sources
Austrian Diabetes Society
Diabetes mellitus – definition, classification, diagnosis, screening, and prevention, update 2026
Austrian Health Portal
Diabetes: diagnosis
Austrian Health Portal
Haemoglobin A1c (HbA1c)
Austrian Diabetes Society
Antihyperglycaemic therapy in type 2 diabetes mellitus – update 2026
Austrian Diabetes Society
Geriatric aspects in diabetes mellitus (update 2026)
Austrian Diabetes Society
Diabetes mellitus in childhood and adolescence (update 2026)
Medical Advice
The information on this website is intended for general guidance only and does not replace an individual medical consultation, examination, or diagnosis. In the event of symptoms or health-related questions, please consult your physician.