Anemia is a medical condition characterized by a reduced number of healthy red blood cells or a decrease in their hemoglobin content, leading to insufficient oxygen delivery to tissues. Normocytic anemia is a specific type where red blood cells are of normal size but are insufficient in number or function.
What is Normocytic Anemia?
Red blood cell size is measured by Mean Corpuscular Volume (MCV). In normocytic anemia, the MCV typically falls within the normal range, usually between 80 and 100 femtoliters (fL). This distinguishes it from microcytic anemias, where red blood cells are smaller, and macrocytic anemias, where they are larger. Despite their normal size, the primary issue is either a reduced production of these cells or their increased destruction or loss.
Common Causes of Normocytic Anemia
Acute Blood Loss
Significant and sudden blood loss is a common cause of normocytic anemia. This can occur due to trauma, surgery, or internal bleeding from conditions like gastrointestinal hemorrhage. When a large volume of blood is lost rapidly, the body’s total red blood cell count decreases, but the remaining red blood cells are initially of normal size. The body’s immediate response involves drawing fluid into the bloodstream, diluting the remaining blood and making the reduced red blood cell count more apparent.
Anemia of Chronic Disease
Anemia of chronic disease (ACD), also known as anemia of inflammation, is a frequent cause of normocytic anemia, often considered the most common type. This condition develops in individuals with long-term inflammatory conditions, infections, autoimmune disorders, or cancers. The chronic inflammation interferes with the body’s ability to properly use iron and can suppress red blood cell production in the bone marrow. While the red blood cells produced are typically of normal size, their overall production is hindered, leading to a lower count.
Kidney Disease
Chronic kidney disease (CKD) is another significant cause of normocytic anemia. Healthy kidneys produce a hormone called erythropoietin (EPO), which signals the bone marrow to produce red blood cells. In individuals with kidney damage, the kidneys produce less EPO, which directly reduces the bone marrow’s ability to make new red blood cells. Consequently, fewer red blood cells are formed, but those that are produced are generally normal in size, resulting in normocytic anemia.