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 persons blood is less than normal or the red blood
cells dont 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 dont
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 arent enough
red blood cells, or not enough hemoglobin in the red blood cells, the blood
cant 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 cant produce
them fast enough to meet the bodys 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 bodys 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 its not treated.
If you have an inherited form of hemolytic anemia,
its 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 |