What Is Hemolytic Anemia?

Hemolytic anemia (HEE-moh-lit-ick uh-NEE-me-uh) is a rare form of anemia in which red blood cells are destroyed and removed from the bloodstream before their usual lifespan is up. Healthy red blood cells usually live about 120 days (4 months) in the bloodstream before the body removes them. In hemolytic anemia, the body breaks down and removes red blood cells faster than it can replace them. The breakdown of red blood cells is called hemolysis (he-MOL-i-sis).

Anemia

The term “anemia” means that the number of red blood cells in a person’s blood is less than normal or the red blood cells don’t contain enough hemoglobin (HEE-moh-glow-bin). Hemoglobin is an iron-rich protein in red blood cells that gives blood its red color. Anemia is also known as having a “low blood count.”

The most common symptom of anemia is fatigue (tiredness). Fatigue develops because the tissues of the body don’t receive enough oxygen. The hemoglobin in red blood cells picks up oxygen in the lungs and circulates it to the tissues of the body. If there aren’t enough red blood cells, or not enough hemoglobin in the red blood cells, the blood can’t carry enough oxygen to the rest of the body.

Red blood cells also are called RBCs or erythrocytes (eh-RITH-roh-sites). Normal red blood cells are all about the same size and look like tiny doughnuts without holes in the center. Normal red blood cells have an average lifespan of 120 days, after which they die and are removed from the bloodstream. The iron in the hemoglobin is recycled to make new red blood cells. The marrow inside the large bones of the body continually produces new red blood cells to replace the ones that have died.

The blood also contains two other types of cells: white blood cells and platelets. White blood cells help fight infection. Platelets help blood to clot. In some kinds of anemia, there are low amounts of all three types of blood cells.

There are three main causes of anemia: blood loss, lower than normal levels of red blood cell production, or higher than normal rates of red blood cell destruction. More than one of these factors can combine to cause anemia.

Hemolytic Anemia

Hemolytic anemia is due to increased hemolysis (destruction) of red blood cells. The bone marrow increases production of red blood cells to replace the hemolyzed blood cells, but it can’t produce them fast enough to meet the body’s needs.

In some types of hemolytic anemia, the body makes abnormal red blood cells that break down and hemolyze on their own. In other types of hemolytic anemia, the body’s immune system, infections, certain drugs, or other agents attack normal red blood cells, causing them to hemolyze. The hemolysis can occur in the bloodstream or in an organ called the spleen.

The two main types of hemolytic anemia are inherited and acquired. In inherited hemolytic anemia, the condition is passed from parent to child. In acquired hemolytic anemia, the person develops the condition from some other cause. Hemolytic anemia can begin rapidly or come on gradually and can range from mild to severe.

Outlook

Hemolytic anemia can often be successfully treated or controlled. The course of hemolytic anemia depends on the cause and the severity of the anemia. Mild hemolytic anemia may need no treatment at all. Severe hemolytic anemia can be life threatening if it’s not treated.

If you have an inherited form of hemolytic anemia, it’s a lifelong condition that requires ongoing treatment. If your anemia is caused by an infection or use of a particular medicine, the anemia may go away when the infection is treated or when the medicine is stopped.

September 2006