Anemia according to morphology of red blood cells:

On the basis of morphology of red blood cells, anemia are of following types:

1. Macrocytic normochromic anemia:

• This type of anemia denotes the presence of immature red blood cells in blood.
• It occurs due to deficiency of vitamin B₁₂, folic acid, cobalt, intrinsic factors and erythrocyte maturation factors.
• Size of RBCs is increased in this type of anemia and bone marrow is responsive.

2. Macrocytic hypochromic anemia:

• This anemia occurs in regenerative phases after hemorrhage.
• Hemorrhage may be due to trauma, wound, surgical bleeding, parasitic oozing of blood, epistaxis, etc.
• Size of RBC is increased with decreased Hb concentration.

3. Normocytic normochromic anemia:

• This is known as aplastic or hypoplastic anemia.
• Staining properties of RBC’s are normal. Number of granulocytes and thrombocytes are reduced
• It occurs due to suppression of bone marrow activity in acute or sub-acute systemic disease.
• It may be primary or secondary. Primary is rare.
• Secondary anemia may occur due to:
  • Chronic hemorrhage
  • Neoplasm
  • Deficiency of vitamin-6 and prothrombin
  • Ionization and irradiation
  • Chemical poisoning
  • Bracken fern poisoning
  • Sulphonamide and chloramphenicol toxicity
• Size of RBC is normal with normal hemoglobin concentration.

4. Normocytic hypochromic anemia:

• This type of anemia occurs due to reduced hemoglobin formation.
• Size of R.B.C is normal with reduced hemoglobin concentration.
• This anemia occurs due to following factors/causes:
  • Dietary deficiency of iron; due to exclusive intake of milk in piglets or defective absorption of iron
  • Dietary deficiency of copper
  • Dietary deficiency of ascorbic acid (Vitamin-C)
  • Dietary deficiency of pyridoxine
  • Dietary deficiency of nicotinic acid
  • Dietary deficiency of riboflavin
  • Deficiency of thyroxine

5. Microcytic normochromic anemia:

• In this type of anemia, size of RBC is reduced with normal hemoglobin concentration
• This anemia occurs due to following causes:
  • Chemical poisoning
  • Chronic interstitial nephritis
  • Worm infection
  • Chronic infection like tuberculosis, brucellosis
  • Ionizing radiation

6. Microcytic hypochromic anemia:

• This anemia result due to deficiency of iron.
• It also occurs due to dietary deficiency of copper, manganese, cobalt, ascorbic acid, pyridoxine, nicotinic acid, riboflavin, thyroxin, etc.
• Size of RBCs are reduced with reduced hemoglobin concentration.