Types of Anemia

Jun 23, 2024

Lecture on Types of Anemia

What is Anemia?

  • Definition: Low oxygen-carrying capacity of blood
    • Can be due to decrease in number of red blood cells (RBCs) or dysfunctional RBCs
  • Symptoms: Shortness of breath (dyspnea), fatigue, increased workload on the heart, tachycardia, dizziness, potential syncope

Types of Anemia

1. Iron Deficiency Anemia

  • Cause: Deficiency in iron
    • Needed for hemoglobin production (iron + protoporphyrin 9 → heme)
    • Low iron → low heme → low hemoglobin → small RBCs (microcytic anemia)
  • Symptoms: Fatigue, shortness of breath, tachycardia, dizziness, increased workload on heart
  • Causes: Blood loss (ulcers, heavy menstruation), low iron diet (common in vegetarians)
  • Diagnosis: Low Mean Corpuscular Volume (MCV < 90 fL)
  • Treatment: Iron supplements, possibly transfusions

2. Pernicious Anemia (B-12/Folic Acid Deficiency)

  • Cause: Autoimmune destruction of parietal cells→ low intrinsic factor → decreased B-12 absorption
  • Symptoms: Large RBCs (macrocytic anemia), fatigue, shortness of breath
  • Diagnosis: High Mean Corpuscular Volume (MCV > 90 fL)
  • Treatment: Intramuscular B-12 injections, folic acid supplements

3. Hereditary Spherocytosis

  • Cause: Genetic mutation affecting RBC membrane proteins (spectrin, ankyrin)
  • Symptoms: Spherical RBCs, hemolysis, splenomegaly
  • Diagnosis: Usually microcytic, detected via Coombs test
  • Treatment: Managing symptoms, possibly splenectomy

4. G6PDH Deficiency

  • Cause: Deficiency in glucose-6-phosphate dehydrogenase enzyme, important for protecting RBCs from oxidative damage
  • Symptoms: Hemolytic anemia, Heinz bodies in RBCs
  • Diagnosis: Detection of Heinz bodies
  • Treatment: Avoidance of trigger substances, managing oxidative stress

5. Sickle Cell Anemia

  • Cause: Genetic mutation (missense) replacing glutamic acid with valine in hemoglobin
  • Symptoms: Sickle-shaped RBCs, vaso-occlusive crises (e.g., priapism, splenomegaly)
  • Diagnosis: Identified by hemoglobin electrophoresis
  • Treatment: Oxygen therapy, pain management, hydroxyurea to increase fetal hemoglobin, blood transfusions

6. Hemorrhagic Anemia

  • Cause: Acute or chronic blood loss (injuries, peptic ulcers)
  • Symptoms: Loss of RBCs → anemia symptoms
  • Diagnosis: Based on clinical history of blood loss
  • Treatment: Red blood cell transfusions, fluids, surgical intervention if necessary

7. Aplastic Anemia

  • Cause: Bone marrow failure (drugs, radiation, infections)
  • Symptoms: Pancytopenia (low RBCs, WBCs, platelets), increased infections, bruising/bleeding
  • Diagnosis: Pancytopenia on blood tests
  • Treatment: Bone marrow transplant, symptomatic treatment (antibiotics, transfusions)

8. Thalassemia

  • Cause: Genetic mutation in globin chain synthesis (alpha or beta)
  • Symptoms: Microcytic anemia, chronic transfusion dependence
  • Diagnosis: Low MCV (<90 fL), family history
  • Treatment: Regular transfusions, iron supplements, possible bone marrow transplant

Conclusion

  • Overview of various types of anemia, their causes, symptoms, diagnoses, and treatments
  • Emphasis on the unique characteristics of each type

Additional Notes

  • Some anemias might require splenectomy (e.g., hereditary spherocytosis, sickle cell anemia)
  • Importance of understanding the underlying causes to determine appropriate treatment