Anemia also known as Haematological Diseases 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 sign, not 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,band paleness which is due to low hemoglobin content.
Types of Anemia |Types Of Haematological Diseases
- Iron deficiency anemia
- Pernicious anemia
- Sickle cell anemia
- Megaloblastic anemia
- Anemia of chronic disease
- Hemolytic anemia
- Idiopathic aplastic anemia
- Thalassemia
Epidemiology Of Haematological Diseases Or Anemia
A moderate degree of iron-deficiency anemia/haematological diseases 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 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. The thalassemias are the most common genetic blood diseases and are found in Southeast Asia and in areas where sickle cell disease is common.
Causes Of Haematological Disease Or 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.
Causes of Common Types of Anemia/Haematological Disease : Common types of anemia and their causes include:
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, body cannot produce enough hemoglobin for red blood cells.
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 inability of 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.
Anemias associated with bone marrow disease: A variety of diseases, such as leukemia, myelodysplasia or myelofibrosis, can cause anemia by affecting blood production in bone marrow. The effects of these types of cancer and cancer like disorders vary from a mild alteration in blood production to a complete life threatening shutdown of the blood making process. Other cancers of the blood or bone marrow, such as multiple myeloma, myeloproliferative disorders and lymphoma also can cause anemia.
Haemolytic anemia: This group of anemias develop when red blood cells are destroyed faster than bone marrow can replace them. Certain blood diseases can cause increased red blood cell destruction. If erythrocyte cell membrane ruptures prematurely, their Hb pours out into plasma (hemolysis). The premature destruction of RBCs may result from inherent defects such as Hb defects, abnormal RBC enzymes or defects of RBC cell membrane. Agents that may cause hemolytic anemia are parasites ,toxins and antibodies from incompatible blood. A person can inherit a hemolytic anemia, or can develop it later in life.
Sickle cell anemia: The erythrocyte of person with Sickle Cell Anemia (SCA) manufactures an abnormal kind of hemoglobin. When such RBC gives up its oxygen to interstitial fluid, the abnormal hemoglobin tend to lose its integrity in place of low oxygen tension and forms long stiff, rod like structure that bind erythrocyte into sickle shape. The sickle cell ruptures easily. Prolonged oxygen reduction may eventually cause extensive tissue damage. Furthermore because of shape of sickle cells, they tend to get stuck in blood vessels and can cut off blood supply to an organ altogether. SCA is characterized by several
symptoms. In young children, hand-feet syndrome is present, in which there is swelling and pain in wrist and feet. Older patients experience pain in back and extremities without swelling and abdominal pain. Other complications include neurological disorders (meningitis, seizure, stroke), impaired pulmonary functions, orthopedic abnormalities, genitourinary tract disorders (involuntary urination, blood in urine, kidney failure) ocular disturbance (hemorrhage, detached retina, blindness) convulsions, coma and infections.
| Hemorrhagic | Acute blood loss. | Normocytic, normochromic, reticulocytosis. |
| Iron-deficiency. | Chronic, slow blood loss; insufficient intake relative to demands. | Microcytic, hypochromic. |
| Hemolytic Sickle cell disease Hereditary spherocytosis Autoimmune Transfusion mismatch Hemoglobinopathies Glucose-6-phosphate dehydrogenase deficiency. | Hereditary defect of RBCs; immune, infectious, mechanical, or traumatic injury of RBCs; hypersplenism. | Variable morphology in hereditary forms (e.g., sickle or spherical shape); normocytic, normochromic in other etiologies. |
| Aplastic or hypoplastic Drug induced Radiation induced Anemia of chronic disease Alcoholism Pernicious anemia Folate deficiency. | Hereditary or nutritional deficiency of substrate for erythropoiesis; bone marrow depression; chronic disease | Macrocytic (megalobastic) in substrate deficiency; normocytic, normochromic in bone marrow depression; microcytic, hypochromic in chronic disease. |