Anemia isn't a disease; it's a symptom-a finger pointing to an underlying disorder. Although you may associate it with blood loss or iron deficiency, it has many other possible causes, ranging from genetic predisposition to sulfonamide use. Anemia occurs with a decrease in the quantity or quality of circulating red blood cells (RBCs), through a malfunction in RBC or hemoglobin production, excessive RBC loss, or abnormal lysis of RBCs. Anemias related to RBC quality may be labeled microcytic (RBCs too small), macrocytic (RBCs too large), hypochromic (hemoglobin concentration too low), or hyperchromic (hemoglobin concentration too high). The terms normocytic and normochromic indicate normal RBC size and hemoglobin concentrations.
Many anemias are classified by their combination of RBC size and hemoglobin concentration: microcytic, hypochromic; normocytic, normochromic; or macrocytic, normochromic. For some possible causes of each class of anemias, see Linking Anemia Classifications to Possible Causes.
Anemias related to RBC quantity occur when RBCs, through loss or lysis, are destroyed or lost earlier than their normal 120-day life expectancy. In hemolytic anemia, for example, RBCs die early and the bone marrow can't produce enough new ones to compensate for the loss.
Regardless of type, anemias cause similar signs and symptoms. Patients commonly complain of fatigue, palpitations, and possibly chest pain or shortness of breath with exertion. On physical examination, you're likely to find pallor, tachycardia, heart murmur, and tachypnea. If the patient has chronic anemia, your assessment findings may include glossitis, brittle or fine hair, and pica. Some anemias are associated with more particular signs and symptoms.
For a look at standard lab tests for anemia, see Looking at Values for Three Common Anemias. Other tests may be needed depending on the anemia suspected and the cause. (Little, D.: " 59(6):1598-1604, March 15, 1999. )............
