Sickle Cell Disease

What is sickle cell disease?

Sickle cell disease (SCD) is an
inherited blood disorder. This means it is passed down from a parent’s genes. It causes
the body to make abnormal hemoglobin. This is the protein in red blood cells that
carries oxygen to all parts of your body. When you have SCD, your body’s tissues and
organs don’t get enough oxygen.

Healthy red blood cells are round and move easily all over the body. With SCD, the red blood cells are hard and sticky. They are shaped like the letter C (and like a farm tool called a sickle). These damaged red blood cells (sickle cells) clump together. They can’t move easily through the blood vessels. They get stuck in small blood vessels and block blood flow. This blockage stops the movement of healthy oxygen-rich blood. This blockage can cause pain. It can also damage major organs.

Sickle cells die sooner than healthy cells. Normally the spleen helps filter infections out of the blood. But sickle cells get stuck in this filter and die. Having fewer healthy red blood cells causes anemia. The sickle cells can also damage the spleen. This puts you at greater risk for infections.

What causes sickle cell disease?

Sickle cell is an inherited disease caused by a defect in a gene.

  • You are born with SCD only if two genes are inherited—one from each parent.
  • If you have just one gene you are healthy, but you are a carrier of the disease. If two carriers have a child, there is a greater chance their child will have SCD.
  • Parents who are each carriers of a
    sickle cell gene have a 1 in 4 chance of having a child with SCD.

Who is at risk for sickle cell disease?

Having a family history of sickle cell disease increases your risk for the disease. SCD mainly affects people whose families came from Africa, and Hispanics whose families are from the Caribbean. But the gene has also been found in people whose families are from the Middle East, India, Latin America, and Mediterranean countries. It has also been found in Native American Indians.

What are the symptoms of sickle cell disease?

Each person’s symptoms may vary. They may be mild or severe. Symptoms may include:

  • Anemia. This is the most common
    symptom. Having fewer red blood cells causes anemia. Severe anemia can make you feel
    dizzy, short of breath, and tired.
  • Yellowing of the skin, eyes, and mouth
    (jaundice). 
    This is a common symptom. Sickle cells don’t live as long as
    normal red blood cells. They die faster than the liver can filter them out. The
    yellow color is caused by a substance (bilirubin) that is released when the red blood
    cells die.
  • Pain crisis, or sickle crisis. When
    sickle cells move through small blood vessels, they can get stuck. This blocks blood
    flow and causes pain. The sudden pain can occur anywhere. But it most often happens
    in the chest, arms, and legs. Blocked blood flow may also cause tissue death.
  • Acute chest syndrome. This is when
    sickle cells stick together and block oxygen flow in the tiny vessels in the lungs.
    This can be life-threatening. It often happens suddenly, when the body is under
    stress from infection, fever, or dehydration. Symptoms may seem like pneumonia. They
    can include fever, pain, and a violent cough.
  • Splenic sequestration (pooling). The
    spleen becomes enlarged and painful when sickle cells get stuck there. Fewer red
    blood cells are able to move. This can cause a sudden drop in hemoglobin. It can be
    deadly if not treated at once.
  • Stroke. This is another sudden and
    severe problem that occurs with this disease. The sickle cells can block the major
    blood vessels that bring oxygen to the brain. Any interruption in the flow of blood
    and oxygen to the brain can cause severe brain damage. If you have a stroke from SCD,
    you are more likely to have a second and third stroke.
  • Priapism. The sickle cells block the
    blood vessels in the penis, causing great pain. If not treated right away, it can
    cause impotence.

The symptoms of SCD may look like other blood disorders or health problems. Always see your healthcare provider for a diagnosis.

How is sickle cell disease diagnosed?

Your healthcare provider will take
your health history and give you a physical exam. You may also have blood tests and
other tests.

Many states routinely screen newborns for sickle cell. This allows treatment to begin as soon as possible. Early diagnosis and treatment can reduce the risk of problems.

A blood test called hemoglobin electrophoresis may be done. It can tell if you are a carrier of sickle cell. It can also tell if you have any of the diseases linked with the sickle cell gene.