What Is Sickle Cell Anemia?
Sickle cell anemia (uh-NEE-me-uh) is a serious
disease in which the body makes sickle-shaped red blood cells.
Sickle-shaped means that the red blood cells are shaped like a
"C."
Normal red blood cells are disc-shaped and look like
doughnuts without holes in the center. They move easily through your blood
vessels. Red blood cells contain the protein hemoglobin (HEE-muh-glow-bin).
This iron-rich protein gives blood its red color and carries oxygen from the
lungs to the rest of the body.
Sickle cells contain abnormal hemoglobin that causes
the cells to have a sickle shape. Sickle-shaped cells dont move easily
through your blood vessels. Theyre stiff and sticky and tend to form
clumps and get stuck in the blood vessels. (Other cells also may play a role in
this clumping process.)
The clumps of sickle cells block blood flow in the
blood vessels that lead to the limbs and organs. Blocked blood vessels can
cause pain, serious infections, and organ damage.
Normal and Sickled Red Blood
Cells
Figure A shows normal
red blood cells flowing freely in a blood vessel. The inset image shows a
cross-section of a normal red blood cell with normal hemoglobin. Figure B shows
abnormal, sickled red blood cells clumping and blocking blood flow in a blood
vessel. (Other cells also may play a role in this clumping process.) The inset
image shows a cross-section of a sickle cell with abnormal hemoglobin.
Overview
Sickle cell anemia is one type of
anemia.
Anemia is a condition in which your blood has a lower than normal number of red
blood cells. This condition also can occur if your red blood cells dont
have enough hemoglobin.
Red blood cells are made in the spongy marrow inside
the large bones of the body. Bone marrow is always making new red blood cells
to replace old ones. Normal red blood cells last about 120 days in the
bloodstream and then die. They carry oxygen and remove carbon dioxide (a waste
product) from your body.
In sickle cell anemia, a lower-than-normal number of
red blood cells occurs because sickle cells dont last very long. Sickle
cells usually die after only about 10 to 20 days. The bone marrow cant
make new red blood cells fast enough to replace the dying ones.
Sickle cell anemia is an inherited, lifelong
disease. People who have the disease are born with it. They inherit two copies
of the sickle cell geneone from each parent.
People who inherit a sickle cell gene from one
parent and a normal gene from the other parent have a condition called sickle
cell trait. Sickle cell trait is different from sickle cell anemia. People who
have sickle cell trait dont have the disease, but they have one of the
genes that cause it. Like people who have sickle cell anemia, people who have
sickle cell trait can pass the gene to their children.
Outlook
Sickle cell anemia affects millions of people
worldwide. The disease has no widely available cure. However, there are
treatments for the symptoms and complications of the disease.
Bone
marrow transplants may offer a cure in a small number of cases.
Over the past 30 years, doctors have learned a great
deal about sickle cell anemia. They know its causes, how it affects the body,
and how to treat many of its complications.
Sickle cell anemia varies from person to person.
Some people who have the disease have chronic (long-term) pain or fatigue
(tiredness). However, with proper care and treatment, many people who have the
disease can have improved quality of life and reasonable health much of the
time.
Due to improved treatment and care, people who have
sickle cell anemia are now living into their forties or fifties, or longer.
August 2008 |