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Hemoglobin Test

⚠️ Update approaching🔬 Evidence: StrongHematology
Diğer adları: Haemoglobin, Hb, Hemoglobin level
⚠️

Discuss your test results with your doctor. This page is for informational purposes only and does not provide a diagnosis.

⚡ Key Facts

• Measures the level of oxygen-carrying protein in red blood cells • The primary parameter for defining anemia • WHO 2024 thresholds: men <13.0 g/dL, non-pregnant women <12.0 g/dL • Interpreted alongside MCV to guide evaluation of anemia type

🧪 What Does This Test Measure?

The hemoglobin test measures the level of the oxygen-carrying protein in red blood cells, serving as the primary parameter for defining and classifying anemia.

📋 Why Is It Ordered?

Ordered for anemia evaluation, monitoring of existing anemia, erythrocytosis investigation, preoperative assessment, and pregnancy monitoring.

🔧 Preparation

Measured as part of the complete blood count (CBC). No special preparation is generally required; fasting is not necessary.

📊 Reference Ranges

Adult men: ≥13.0 g/dL (≥130 g/L) normal Adult women (non-pregnant): ≥12.0 g/dL (≥120 g/L) normal Pregnant women: ≥11.0 g/dL (1st/3rd trimester), ≥10.5 g/dL (2nd trimester) ⚠️ Thresholds vary by age, sex, altitude, and smoking status.

⬆️ High Values

Elevated hemoglobin (erythrocytosis) may be associated with dehydration, chronic lung disease, high altitude, smoking, or polycythemia vera.

⬇️ Low Values

Low hemoglobin (anemia) may be associated with iron deficiency, B12 or folate deficiency, chronic disease, liver or kidney disease, bone marrow disorders, or blood loss.

⚙️ What Can Affect Results?

Altitude, smoking, pregnancy, dehydration, physical activity, age, sex, and blood collection technique are key factors that may affect hemoglobin results.

🔬 Evidence Summary

Strong evidence: 1 guideline, 1 systematic review, 3 reviews, 2 observational studies.

📚 Most Important Studies on This Topic

1

Guideline on haemoglobin cutoffs to define anaemia in individuals and populations

Guideline· World Health Organization · 2024 · PMID: 38530913

2

Haemoglobin thresholds to define anaemia from age 6 months to 65 years: estimates from international data sources

Observational· Lancet Haematology · 2024 · PMID: 38432242

3

Laboratory diagnosis of anemia: are the old and new red cell parameters useful in classification and treatment, how?

Review· International Journal of Laboratory Hematology · 2016 · PMID: 27195903

✅ Key Takeaways

💡

What you learned: Hemoglobin is the primary parameter for defining anemia. Values below the threshold are evaluated alongside MCV to determine the likely cause.

⛔

A hemoglobin result alone cannot diagnose anemia or determine its cause. Clinical context and additional tests are needed.

🔬 Sources Used on This Page

7 sources · Most recent publication: 2024
📋
Guideline
Expert society and guideline recommendations
1
source
📊
Systematic review / meta-analysis
Combined analysis of multiple studies
1
source
📖
Review
Comprehensive topic evaluation
3
sources
👁
Observational
Observational and cohort studies
2
sources
Overall assessment: Evidence level for this topic is strong. This page is supported by 1 guideline, 1 systematic review/meta-analysis, 3 reviews, 2 observational studies.

📝 Questions to Ask Your Doctor

Be prepared for your appointment. Add questions to your list.

📋 References

[PMID: 38530913] Guideline on haemoglobin cutoffs to define anaemia in individuals and populations. World Health Organization, 2024.
[PMID: 38432242] Haemoglobin thresholds to define anaemia from age 6 months to 65 years: estimates from international data sources. Lancet Haematology, 2024.
[PMID: 32778603] Investigation and management of erythrocytosis. CMAJ, 2020.
[PMID: 31231812] Reexamination of hemoglobin adjustments to define anemia: altitude and smoking. Annals of the New York Academy of Sciences, 2019.
[PMID: 27195903] Laboratory diagnosis of anemia: are the old and new red cell parameters useful in classification and treatment, how?. International Journal of Laboratory Hematology, 2016.
[PMID: 25946282] Iron-deficiency anemia. N Engl J Med, 2015.
[PMID: 24297872] A systematic analysis of global anemia burden from 1990 to 2010. Blood, 2014.
Last reviewed: 4/2/2026
Next review: 4/2/2027

⚖️ Comparisons

Hemoglobin vs Hematocrit→

🔗 Related Topics

🧪 Hemogram (tam kan sayımı)🧪 Ferritin (demir depoları değerlendirmesi)🧪 Serum iron🧪 B12 vitamini (makrositik anemi değerlendirmesi)🧪 Trombosit sayısı
⚖️ This page does not replace medical advice. Make treatment decisions with your doctor.
Content is based on scientific studies indexed in PubMed and current clinical guidelines.