Chronic Anemia

The word "anemia" derives from an ancient Greek word anaimia, meaning "lack of blood." Anemia, like a fever, is not a diagnosis but a presentation of an underlying disease. Multiple diseases can present as anemia due to various mechanisms. Anemia affects a significant number of people worldwide (more so in the developing world), resulting in a considerable increase in the cost of medical care. Anemia can be defined as a reduction in hemoglobin (less than 13.5 g/dL in men; less than 12.0 g/dL in women) or hematocrit (less than 41.0% in men; less than 36.0% in women) or red blood cell (RBC) count. The terms hemoglobin and hematocrit are more commonly used than RBC count in day-to-day clinical practice. There are different lower limits of normal range based on ethnicity, gender, and age. Anemia causes decreased oxygen-carrying capacity of the blood leading to tissue hypoxia. Grading of anemia, according to the National Cancer Institute, is as follows: Anemia is classified into acute anemia and chronic anemia. Acute anemia is predominantly due to acute blood loss or acute hemolysis. Chronic anemia is more common and is secondary to multiple causes.