Overview of Anemia

What is anemia?

Anemia is a common blood disorder that occurs when there are fewer red blood cells than normal, or there is a low concentration of hemoglobin in the blood.

Hemoglobin--the part of blood that distributes oxygen from the lungs to tissues in the body.
Hematocrit--the measurement of the percentage of red blood cells found in a specific volume of blood.

Anemia is often a symptom of a disease rather than a disease itself. Anemia usually develops due to the presence of one of the following:

Excessive blood loss or hemorrhaging
Deficient production of red cells
Excessive red cell destruction
Both decreased production and excessive destruction of red blood cells

What are the symptoms of anemia?

Most symptoms of anemia are a result of the decrease of oxygen in the cells or "hypoxia." Because red blood cells, as hemoglobin, carry oxygen, a decreased production or number of these cells result in "hypoxia." Many of the symptoms will not be present with mild anemia, as the body can often compensate for gradual changes in hemoglobin.

The following are the most common symptoms of anemia. However, each individual may experience symptoms differently. The symptoms may include, but are not limited to, the following:

Abnormal paleness or lack of color of the skin
Increased heart rate (tachycardia)
Breathlessness, or difficulty catching a breath (dyspnea)
Lack of energy, or tiring easily (fatigue)
Dizziness, or faintness, especially when standing
Headache
Irritability
Irregular menstruation cycles
Absent or delayed menstruation (amenorrhea)
Sore or swollen tongue (glossitis)
Jaundice, or yellowing of skin, eyes, and mouth
Enlarged spleen or liver (splenomegaly, hepatomegaly)
Impaired wound and tissue healing

The symptoms of anemia may resemble other blood disorders or medical problems. Because anemia is often a symptom associated with another disease, it is important for your doctor to be aware of symptoms you may be experiencing. Always consult your doctor for a diagnosis.

What causes anemia?

Generally, anemia may be caused by several problems, including the following:

Infections
Certain diseases
Certain medications
Poor nutrition
Blood loss

What are the different types of anemia?

There are several different types of anemia, each with a specific cause and treatment, including the following:

Iron-deficiency anemia
Megaloblastic (pernicious or vitamin B12 deficiency) anemia
Anemia of folate deficiency
Hemolytic anemia
Sickle cell anemia
Cooley's anemia (beta thalassemia)
Aplastic anemia
Chronic anemia
Kidney failure associated anemia

How is anemia diagnosed?

Anemia may be suspected from general findings on a complete medical history and physical examination, such as complaints of tiring easily, pale skin and lips, or a fast heartbeat (tachycardia). Anemia is usually discovered during a medical examination through blood tests that measure the concentration of hemoglobin and the number of red blood cells.

In addition to a complete medical history and physical examination, diagnostic procedures for anemia may include:

Additional blood tests
Bone marrow aspiration and/or biopsy--a procedure that involves taking a small amount of bone marrow fluid (aspiration) and/or solid bone marrow tissue (called a core biopsy), usually from the hip bones, to be examined for the number, size, and maturity of blood cells and/or abnormal cells.