Anemia is considered to be present if the hemoglobin (Hb) concentration is below the lower limit of the 95% reference range for the individual's age, sex, and geografic location.
Causes of Anemia :
Impaired production due to:- Deficiency of Iron, Vitamin B12, Folic acid
Clinical signs and symptoms :Easy fatigability, dyspnea on exertion, faintness, palpitation, headache. The physical findings are pallor, rapid pulse, low B.P., low fever, edema etc.
Nutritional Anemia (Iron Deficiency, Megaloblastic anemia) :- Due to inadequate intake - Increased demand - Defective absorption
Iron deficiency anemia is more common in children, elderly, female in reproductive age group.Sources : green leafy vegetables, cereals, pulses, animal foods(e.g. liver, kidney, meat, egg, yolk) ; cooking in iron vessels. Ascorbic acid (vitamin C) enhances the iron absorption.
Laboratory investigations required are
Treatment- If anemia not severe - modification of diet,Oral iron supplement; for three months.
Megaloblastic anemia RBCs are larger in size Due to vitamin B12 Folic acid deficiency.1. Vitamin B12
Sources of vitamin B12 : liver, eggs, fish, milkLab investigation required are
Treatment- Vitamin B12 rich diet
2. Folic acid deficiency :- This also results in megaloblastic anemia
(II)Increased destruction (Hemolytic Anemia)
Hemoglobin disorders Acquired; Extrinsic causes Immune hemolytic anemia- Anemia that is due to increased red cell destruction is hemolytic anemia.
Hemoglobin disorders - more common are Thalassemias Sickle cell anemia.
- Globin is the protein part is consists of four polypeptide chain.
- Hemoglobin A is the major normal adult hemoglobin, the polypeptide chains of the globin are of two types: two identical a each with 141 amino acid and two b each with 146 amino acid.
In Sickle cell anemia there is a change in one amino acid position of b chain , that makes change in normal hemoglobin. So when there is a change in oxygen tension polymerization of hemoglobin occurs forming tactoids that are rigid and deform the cells into the shape that gave the cells its name. These rigid cells are more vulnerable to hemolysis.Thalassemia
The common characteristic of this disorder is that the rate of synthesis is diminished but the chain formed is in most of the cases structurally normal.In b thalassemias, which are more common, b chain production is decreased.
Most of the patients require regular transfusion.
For long period but in small quantity, e.g. peptic ulcer, malignancy.In case of trauma large quantity of blood is loss at a time may result into acute anemia.