1. Complete Blood Count (CBC) ๐ฉธ
RBC Parameters
- RBC: 4.5-5.5 M/ฮผL (men), 4.0-5.0 (women)
- Hemoglobin: 14-18 g/dL (men), 12-16 (women)
- Hematocrit: 42-52% (men), 37-47% (women)
RBC Indices
- MCV: 80-100 fL (size) - Micro/Normo/Macrocytic
- MCH: 27-31 pg (Hgb per cell)
- MCHC: 32-36% (Hgb concentration) - Hypo/Normochromic
WBC & Differential
- WBC: 4,500-11,000/ฮผL
- Neutrophils: 40-70% (bacterial infections)
- Lymphocytes: 20-40% (viral infections)
- Eosinophils: 1-4% (allergies, parasites)
Platelets
- Count: 150,000-400,000/ฮผL
- <100,000 = Thrombocytopenia
- >400,000 = Thrombocytosis
2. Classification of Anemias ๐ฐ
Microcytic Anemias (MCV <80)
- Iron Deficiency: Most common, low ferritin, high TIBC
- Thalassemia: Target cells, elevated RBC count
- Lead Poisoning: Basophilic stippling
Macrocytic Anemias (MCV >100)
- Vitamin B12 Deficiency: Hypersegmented neutrophils, neuro symptoms
- Folate Deficiency: Similar findings, no neuro symptoms
- Liver Disease/Alcoholism
Normocytic Anemias
- Acute blood loss
- Anemia of chronic disease
- Hemolytic anemias
3. Coagulation Studies ๐ฉน
PT/INR
- Measures Extrinsic pathway (VII)
- Normal PT: 11-15 seconds
- Monitors Warfarin therapy
- INR target: 2.0-3.0 for most patients
aPTT
- Measures Intrinsic pathway (XII, XI, IX, VIII)
- Normal: 25-35 seconds
- Monitors Heparin therapy
- Hemophilia screening
๐ก Board Exam Tips - Hematology
- โ Iron deficiency: Low ferritin, High TIBC
- โ Rule of 3: Hgb ร 3 โ Hct, RBC ร 3 โ Hgb
- โ PT = Warfarin (extrinsic), PTT = Heparin (intrinsic)