Hematological Diseases

Anemia is a medical condition in which the red blood cell count or hemoglobin (Hb) is less than normal. The oxygen-carrying capacity of the blood is therefore, decreased. Red blood cells carry hemoglobin, an iron-rich protein that attaches to oxygen in the lungs and carries it to tissues throughout the body. Anemia is a sign, not a diagnosis. 

There are many kind of anemia, each with its own cause. It is characterized by insufficient erythrocytes or hemoglobin. Loss of blood is the most common cause of anemia. 

Anemia can be temporary or long-term, and it can range from mild to severe. These condition leads to fatigue and intolerance to cold, which related to lack of oxygen needed for energy and heat production, and paleness which is due to low hemoglobin content. 

A moderate degree anemia affected approximately 610 million people worldwide or 8.8% of the population. It is slightly more common in female (9.9%) than males (7.8%). 

Mild iron deficiency anemia affects another 375 million. Prevalence of anemia among non-pregnant women in India is higher than that in other South Asian countries, a recent study published in the reputed medical journal 'The Lancet' has revealed. According to 'The Lancet', anemia affects a quarter of the global population, including 293 million (47%) children younger than 5 and 468 million (30%) non-pregnant women.

Sickle cell disease is common in regions of Africa, India, Saudi Arabia, and the Mediterranean basin. Thalassemias are the most common genetic blood disease and are found in Southeast Asia and in areas where sickle cell disease is common. 

Causes of Anemia

Anemia, like a fever, is a symptom that requires investigation to determine the underlying etiology. Anemia occurs when blood does not have enough red blood cells. This can happen if: 

• Body does not make enough red blood cells. 

• Bleeding causes to lose red blood cells more quickly than they can be replaced. 

• Inherited blood disorder that result in excessive destruction of red blood cells. Iron deficiency anemia: Iron deficiency anemia is caused by a shortage of the element iron in body. Bone marrow needs iron to make hemoglobin. Without adequate iron, the body cannot produce enough hemoglobin for red blood cells. 

Types of Anaemia

Hemorrhagic anemia: Hemorrhagic anemia is specific type of anemia that causes because of sufficient decrease in red blood cells due to hemorrhage (bleeding). Common causes are large wounds, stomach ulcers and heavy menstrual bleeding. 

Megaloblastic anemia: In addition to iron, body needs folate and vitamin B12 to produce sufficient number of healthy red blood cells. A diet lacking in these and other key nutrients can cause decreased red blood cell production. Megaloblastic anemia is marked by the appearance of very large red blood cells. This disorder is caused by incomplete formation of the red blood cell resulting in large numbers of immature and incompletely developed cells. 

Pernicious anemia: In this condition insufficient production of RBCs result from the inability of the body to produce intrinsic factor. As a result, person cannot absorb vitamin B12. Pernicious anemia is deficiency of vitamin B12 due to autoimmune attack on cell of the stomach and antibody against intrinsic factor presented with megaloblastic anemia. 

Anemia of chronic disease: Certain chronic diseases such as cancer, HIV/AIDS, rheumatoid arthritis, Crohn’s disease and other chronic inflammatory diseases can interfere with the production of red blood cells, resulting in chronic anemia. Kidney failure also can cause anemia. 

Aplastic anemia: This is very rare life- threatening anemia caused by a decrease in the bone marrow’s ability to produce red blood cells. Destruction or inhibition of red bone marrow results in aplastic anemia. Typically, the marrow is replaced by fatty tissues or tumour cells. Toxins, γ-radiations, certain medications and autoimmune diseases are causes of aplastic anemia.