anaemia

 Anaemia

Reduction in volume of RBC or in concentration of hemoglobin below lower limit of normal range for age and sex of individual.

In Adults

Hemoglobin (less than 13.5 g/dL in men; less than 12.0 g/dL in women).

In children

Hemoglobin less than <11 g/dL

Classification of anaemia

Anaemia classified into;

1. Based on morphology

(MCV; mean corpuscular volume) and hemoglobin content in RBCs.

2. Based on etiology 

1. Based on morphology

Based on MCV;

1. Microcytic anemia 

Abnormally small RBCs present.

May be present in iron deficiency anemia or non iron deficiency anemia.

For example; thalassemia, Sideroblastic anemia; abnormal utilization of iron during erythropoiesis.

2. Normocytic anemia 

RBCs normal in shape. Anemia occur due to blood loss, hemolysis, bone marrow failure.

3. Macrocytic anemia

RBCs abnormally largein shape. 

It occurs due to vitamin B12, or folic acid deficiency.

For example; megaloblastic anemia.

Based on hemoglobin content in RBCs;

1. Hypochromic anaemia

Abnormally decreased hemoglobin content.

2. Normochromic anaemia

Normal hemoglobin content.

2. Based on etiology

Anemia are;

1. Anemia due to blood loss

a. Acute post Hemorrhagic anemia

b. Chronic post Hemorrhagic anemia

2. Anemia due to impaired red cell production (disturbance in RBC production)

a. For Erythropoiesis essential substance deficiency 

1. Iron deficiency anemia

2. Vitamin B12 and folate deficiency

b. Impairement or disturbance of proliferation and differentiation of stem cells

1. Aplastic anemia

2. Aplasia of pure red cells

c. Due to systemic disease, disturbance of bone marrow function

1. Anaemia due to infection

2. Anaemia due to renal disease

3. Anaemia due to liver disease

4. Anemia due to endocrinopathy

5. Anemia due to disseminated malignancies

d. Anaemia due to bone marrow dysfunction

1. Lukemia

2. Multiple myeloma; cancer that forms in type of white blood cell called a plasma cell

3. Myelosclerosis

Blood is made in organs such as; liver and  spleen, instead of in the bone marrow and bone marrow is replaced by fibrous tissue.

e. Congenital anemia

1. Sickle cell anemia

2. Congenital dyserythropoietic anemia; ineffective erythropoiesis.

3. Anemia due to increased distruction of red blood cells

1. Anaemia due to intracorpuscular defect

a. Sickle cell anemia

b. Thalassemia

2. Anemia due to extracorpuscular defect

a. Hemolytic disease of Newborn

b. Effect of toxic drug

c. Thermal injury/Burn

d. Poisoning from substance like lead

e. Transfusion reaction

f. Infections

Diagnosis of anemia

1. Hemoglobin estimation

2. Peripheral blood fill examination

3. Red Blood cell (RBC) indices 

measure the size, shape, and quality of red blood cells.

Includes; MCH, MCV, MCHC 

Mean corpuscular volume (MCV): Measures the average size of red blood cells.

Mean corpuscular hemoglobin (MCH): Measures the average amount of hemoglobin in red blood cells.

MCHC; mean corpuscular hemoglobin concentration;  measure the average concentration of hemoglobin in red blood cells.

4. Leukocyte, reticulocyte and platelet count

In anemia due to hemolysis of blood, neutrophils and platelet count elevated. 

In infection and leukemia, leucocyte count high and immature leucocytes appear in blood.

5. Bone marrow examination

Cellular changes within bone marrow.