Anemia

Anemia Definition
Anemia, also called anaemia, is a condition in which your blood has a lower than normal number of red blood cells. Red blood cells are produced through a series of complex and specific steps. They are made in the bone marrow, and when all the proper steps in their maturation are complete, they are released into the blood stream. The hemoglobin molecule is the functional unit of the red blood cells and is the protein structure that is inside the red blood cells. Anemia also can occur if your red blood cells don’t contain enough hemoglobin. Hemoglobin is an iron-rich protein that gives blood its red color. This protein helps red blood cells carry oxygen from the lungs to the rest of the body. The normal level of hemoglobin is generally different in males and females. For men, anemia is typically defined as hemoglobin level of less than 13.5 gram/100ml and in women as hemoglobin of less than 12.0 gram/100ml.

Anemia is the most common disorder of the blood. Women and people with chronic diseases are at increased risk of the condition. Important factors to remember are:
Certain forms of anemia are hereditary and infants may be affected from the time of birth.
Women in the childbearing years are particularly susceptible to a form of anemia called iron-deficiency anemia because of the blood loss from menstruation and the increased blood supply demands during pregnancy.
Seniors also may have a greater risk of developing anemia because of poor diet and other medical conditions.

Types of anemia
There are more than 400 types of anemia, which are divided into follow:
Excessive blood loss (acutely such as a hemorrhage or chronically through low-volume loss);
Excessive blood cell destruction (hemolysis);
Decreased or Faulty Red Blood Cell Production (ineffective hematopoiesis):

• Sickle cell anemia
• Iron deficiency anemia
• Vitamin deficiency
• Bone marrow and stem cell problems (Aplastic anemia, Thalassemia)
• Other health conditions.

Classified according to the size of the red blood cells, are three major types of anemia:
If the red blood cells are smaller than normal, this is called microcytic anemia:
Microcytic anemia is primarily a result of hemoglobin synthesis failure/insufficiency, which could be caused by several etiologies:

• Heme synthesis defect: Iron deficiency anemia;
• Globin synthesis defect: alpha-, and beta-thalassemia (inherited disorders of hemoglobin);
• Sideroblastic defect.

If the red blood cells size are normal in size (but low in number), this is called normocytic anemia:
Normocytic anaemia occurs when the overall hemoglobin levels are always decreased, but the red blood cell size (Mean corpuscular volume) remains normal.

• Acute blood loss
• Anemia of chronic disease
• Anemia of kidney disease
• Aplastic anemia (bone marrow failure)
• Hemolytic anemia .

If red blood cells are larger than normal, then it is called macrocytic anemia.

• Megaloblastic anemia
• Pernicious anemia
• Vitamin deficiency anemia
• Folic acid deficiency anemia
• Alcoholism anemia.