Anemia - Diagnosis

Diagnosis

The first step in any diagnosis is a physical examination to determine if the patient has symptoms of anemia and any complications. Because anemia may be the first symptom of a serious illness, determining its cause is very important. This may be difficult, particularly in the elderly, malnourished, or people with chronic diseases, whose anemia may be caused by one or more factors. A detailed medical, personal, and dietary history should report:

• Any family or personal history of anemia
• A history of gallbladder disease, jaundice, or enlarged spleen
• Heavy menstrual bleeding in women
• Any occurrence of blood in the stool or other signs of internal bleeding. (Even if the patient has not observed any bleeding, nonvisible blood may be present, so a rectal exam and stool test are essential.)
• Any dietary history, particularly in people who are elderly, poor, or both

The doctor should examine the patient carefully, especially checking for swollen lymph nodes, an enlarged spleen, and pale skin and nail color.

Blood Tests to Determine the Presence of Any Anemia

For anemia from any cause, specific blood tests are given to determine anemia from any cause.

Blood and Hemoglobin Counts. A complete blood count (CBC) test is performed to determine the presence of anemia. The red blood cells, or erythrocytes, and their iron-bearing component, hemoglobin, are measured.

For example, severe anemia in adults is defined by the World Health Organization as:

• Hemoglobin concentrations below 7.5 mmol/L (12 g/dL) in women. (Some evidence suggests that in older women anemia should be diagnosed at 13 g/dL and below.)
• Below 8.1 mmol/L (13 g/dL) in men.

A low red blood cell (RBC) count could indicate a number of problems, including bleeding or a failure by bone marrow to manufacture red blood cells.

Hematocrit. Calculating the percentage of red blood cells in blood plasma (a measurement called the hematocrit) is also important. Plasma is the liquid portion of blood. People with a high volume of plasma may be anemic even if their blood count is normal because the blood cells have become diluted.