Interpret Your Hemoglobin Results
Enter your Hgb value below and get an instant, free AI interpretation — a plain-English explanation checked against WHO/IFCC reference ranges.
Medical Disclaimer
This AI-generated interpretation is for educational purposes only and does not constitute medical advice, diagnosis, or treatment. Results may vary based on individual health factors not captured here.
Always consult a qualified healthcare professional before making any health decisions. Read full disclaimer →
Hemoglobin Normal Ranges
Hemoglobin (Hgb) is the iron-containing protein in red blood cells responsible for carrying oxygen from the lungs to body tissues and returning carbon dioxide to the lungs.
| Age Group | Sex | Reference Range | Unit | Notes |
|---|---|---|---|---|
| Adults (18–64) | Male | 13.5 – 17.5 | g/dL | — |
| Adults (18–64) | Female | 12 – 15.5 | g/dL | — |
| All ages | Female | 11 – 14 | g/dL | Pregnancy |
| Children / Pediatric | All | 11 – 16 | g/dL | Age 6 months–12 years (approximate) |
Also reported in: g/L, mmol/L.
Critical (Panic) Values
Critical Low: < 7 g/dL. Critical High: > 20 g/dL. Values outside these limits require immediate clinical attention.
Why Doctors Order the Hemoglobin Test
Hemoglobin is the cornerstone test for diagnosing anemia and polycythemia. It guides decisions about blood transfusions, iron supplementation, and treatment of bone marrow disorders.
How to Enter Your Hgb Result
Hemoglobin can be reported in g/dL, g/L or mmol/L. Choose the unit printed next to your result on the lab report so it is compared with the matching reference range.
Reference ranges for Hgb differ by age and between men and women, so entering your age and sex gives a more accurate reading.
What a Low or High Hgb Can Be Associated With
Below the reference range
- Iron deficiency anemia (most common worldwide)
- Vitamin B12 or folate deficiency (megaloblastic anemia)
- Chronic kidney disease (reduced erythropoietin)
- Thalassemia and hemoglobinopathies
- Bone marrow failure (aplastic anemia)
Above the reference range
- Polycythemia vera (bone marrow overproduction)
- Chronic mountain sickness / high-altitude living
- Dehydration / hemoconcentration
- Chronic obstructive pulmonary disease (COPD)
- Heavy smoking (carbon monoxide effect)
This interpreter flags a result at or below 7 g/dL or at or above 20 g/dL as a critical value. Results that extreme are uncommon — contact your doctor promptly, and seek urgent medical care if you feel unwell.
These are common associations, not a diagnosis. A single result is read alongside your symptoms, history and other tests — discuss it with your doctor.
What Can Change Your Hgb Result
Before you read too much into a result, consider whether any of these applied:
- Recent blood transfusion (falsely raises result)
- High-altitude residence (naturally higher baseline)
- Severe dehydration (falsely elevated due to hemoconcentration)
- Pregnancy (physiologically lower due to plasma expansion)
Preparing for the test: No special preparation is required for a hemoglobin test. It is typically drawn as part of a complete blood count (CBC) from a routine blood draw.
Symptoms That Often Prompt Hgb Testing
- Fatigue and weakness
- Shortness of breath on exertion
- Pale or yellowish skin
- Dizziness or lightheadedness
- Rapid or irregular heartbeat
Want the full clinical guide to Hemoglobin?
Reference ranges, causes, symptoms, preparation, and FAQs.