Hematology Quick Reference
Hemoglobin • WBCs • Platelets • Critical Values
Vital Lab Data Visualization
Understanding the Complete Blood Count
Laboratory values are the compass by which clinicians navigate patient health. This infographic breaks down the three pillars of a standard hematology panel: Hemoglobin (oxygen transport), White Blood Cells (immune defense), and Platelets (coagulation). Understanding the normal variations across age and sex is crucial for accurate diagnosis.
⚠️ Reference ranges may vary by laboratory. Always consult local lab standards.
1. Hemoglobin (Hb): The Oxygen Carrier
Hemoglobin measures the oxygen-carrying capacity of the blood. Normal ranges vary significantly by age and sex. Key Insights:
- Newborns have the highest Hb levels to survive the hypoxic environment of the womb.
- Men generally have higher Hb than women due to hormonal differences (testosterone stimulates erythropoiesis).
- Low Hb (Anemia): Fatigue, pallor, shortness of breath.
- High Hb (Polycythemia): Risk of clotting, caused by dehydration or lung disease.
Figure 1: Normal Hemoglobin Ranges (g/dL) by Demographic
2. White Blood Cells (WBC)
WBCs are the immune system’s mobile defense units. Notice the trend: children have higher “normal” baselines than adults.
Infection (Bacterial), Stress, Inflammation, Steroids.
Viral infection, Chemo, Aplastic Anemia.
3. The Differential breakdown
Not all WBCs are the same. The “Diff” reveals which specific soldier is fighting the battle.
4. Platelets & Critical Safety Zones
Platelets are essential for clotting. The normal range is wide (150k – 450k), but deviations can be dangerous.
⚠️ Summary Cheat Sheet: Critical Values
| Test | Normal (Adult) | CRITICAL |
|---|---|---|
| Hemoglobin | 12.0 – 17.5 g/dL | < 7.0 or > 21.0 |
| WBC | 4.5 – 11.0 k/µL | < 2.0 or > 30.0 |
| Platelets | 150 – 450 k/µL | < 20 or > 1,000 |
*Immediate clinical attention required.