Anemia is the blood disorder, characterized by the reduction in Red blood cell (RBC) count, Hemoglobin content and Packed cell volume (PVC). Generally, reduction in RBC count, hemoglobin content and PCV occurs because of decreased production of RBC,increased destruction of RBC and excess loss of blood from the body.All these incidents are caused either by inherited disorders or environmental influences such as nutritional problem, infection and exposure to drugs or toxins.
Morphological classification depends upon the size and color of RBC. Size of RBC is determined by mean corpuscular volume (MCV). Color is determined by mean corpuscular hemoglobin concentration (MCHC). By this method, the anemia is classified into four types :
1. Normocytic Normochromic Anemia Size (MCV) and color (MCHC) of RBCs are normal. But
the number of RBC is less.
2. Macrocytic Normochromic Anemia RBCs are larger in size with normal color. RBC count is
less.
3. Macrocytic Hypochromic Anemia RBCs are larger in size. MCHC is less, so the cells are
pale (less colored).
4. Microcytic Hypochromic Anemia RBCs are smaller in size with less color.
Nutrition Deficiency Anemia
Anemia that occurs due to deficiency of a nutritive substance necessary for erythropoiesis is called nutrition
deficiency anemia. The substances which are necessary for erythropoiesis are iron, proteins and vitamins like
C, B12 and folic acid. The types of nutrition deficiency anemia are:
Iron deficiency anemia
Iron deficiency anemia is the most common type of anemia. It develops due to inadequate availability of
iron for hemoglobin synthesis. RBCs are microcytic and hypochromic.
Causes of iron deficiency anemia:
nails (koilonychias), brittle hair, atrophy of papilla in tongue and dysphagia (difficulty in swallowing).
Protein deficiency anemia
Due to deficiency of proteins, the synthesis of hemo globin is reduced. The RBCs are macrocytic and hypochromic.
Pernicious anemia or Addison’s anemia
Pernicious anemia is the anemia due to deficiency of vitamin B12. It is also called Addison’s anemia. It is due
to atrophy of the gastric mucosa because of autoimmune destruction of parietal cells. The gastric atrophy results in decreased production of intrinsic factor and poor absorption of vitamin B12, which is the maturation factor for RBC. RBCs are larger and immature with almost normal or slightly low hemoglobin level. Synthesis of hemoglobin is almost normal in this type of anemia. So, cells are macrocytic and normochromic/hypochromic. Before knowing the cause of this anemia, it was very difficult to treat the patients and the disease was considered to be fatal. So, it was called pernicious anemia. Pernicious anemia is common in old age and it is more common in females than in males. It is associated with other autoimmune diseases like disorders of thyroid gland, Addison’s disease, etc.
Symptoms
lemon yellow color of skin (due to anemic paleness and mild jaundice) and red sore tongue.
Neurological disorders such as paresthesia (abnormal sensations like numbness, tingling, burning, etc.), progressive weakness and ataxia (muscular incoordination) are also observed inextreme conditions.
Megaloblastic anemia
Megaloblastic anemia is due to the deficiency of maturation factor called folic acid. Here, the RBCs are
not matured. The DNA synthesis is also defective, so the nucleus remains immature. The RBCs are megaloblastic and hypochromic.
Morphological classification depends upon the size and color of RBC. Size of RBC is determined by mean corpuscular volume (MCV). Color is determined by mean corpuscular hemoglobin concentration (MCHC). By this method, the anemia is classified into four types :
1. Normocytic Normochromic Anemia Size (MCV) and color (MCHC) of RBCs are normal. But
the number of RBC is less.
2. Macrocytic Normochromic Anemia RBCs are larger in size with normal color. RBC count is
less.
3. Macrocytic Hypochromic Anemia RBCs are larger in size. MCHC is less, so the cells are
pale (less colored).
4. Microcytic Hypochromic Anemia RBCs are smaller in size with less color.
Nutrition Deficiency Anemia
Anemia that occurs due to deficiency of a nutritive substance necessary for erythropoiesis is called nutrition
deficiency anemia. The substances which are necessary for erythropoiesis are iron, proteins and vitamins like
C, B12 and folic acid. The types of nutrition deficiency anemia are:
Iron deficiency anemia
Iron deficiency anemia is the most common type of anemia. It develops due to inadequate availability of
iron for hemoglobin synthesis. RBCs are microcytic and hypochromic.
Causes of iron deficiency anemia:
- Loss of blood
- Decreased intake of iron
- Poor absorption of iron from intestine
- Increased demand for iron in conditions like growth and pregnancy.
nails (koilonychias), brittle hair, atrophy of papilla in tongue and dysphagia (difficulty in swallowing).
Protein deficiency anemia
Due to deficiency of proteins, the synthesis of hemo globin is reduced. The RBCs are macrocytic and hypochromic.
Pernicious anemia or Addison’s anemia
Pernicious anemia is the anemia due to deficiency of vitamin B12. It is also called Addison’s anemia. It is due
to atrophy of the gastric mucosa because of autoimmune destruction of parietal cells. The gastric atrophy results in decreased production of intrinsic factor and poor absorption of vitamin B12, which is the maturation factor for RBC. RBCs are larger and immature with almost normal or slightly low hemoglobin level. Synthesis of hemoglobin is almost normal in this type of anemia. So, cells are macrocytic and normochromic/hypochromic. Before knowing the cause of this anemia, it was very difficult to treat the patients and the disease was considered to be fatal. So, it was called pernicious anemia. Pernicious anemia is common in old age and it is more common in females than in males. It is associated with other autoimmune diseases like disorders of thyroid gland, Addison’s disease, etc.
Symptoms
lemon yellow color of skin (due to anemic paleness and mild jaundice) and red sore tongue.
Neurological disorders such as paresthesia (abnormal sensations like numbness, tingling, burning, etc.), progressive weakness and ataxia (muscular incoordination) are also observed inextreme conditions.
Megaloblastic anemia
Megaloblastic anemia is due to the deficiency of maturation factor called folic acid. Here, the RBCs are
not matured. The DNA synthesis is also defective, so the nucleus remains immature. The RBCs are megaloblastic and hypochromic.
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