Sickle cell anemia is the most common form of sickle cell disease (SCD).
SCD is a serious disorder in which the body makes sickle-shaped red blood cells.
Sickle cells contain abnormal hemoglobin called sickle hemoglobin or hemoglobin S.
It causes the cells to develop a sickle, or crescent, shape.
Sickle cells are stiff and sticky. They often block blood flow in the blood vessels of the limbs and organs. Blocked blood flow can cause pain and organ damage and raise the risk for infection. Normal red blood cells live about 120 days in the bloodstream and then die.
In sickle cell anemia, the abnormal sickle cells usually die after only about 10 to 20 days. The bone marrow can't make new red blood cells fast enough to replace the dying ones.
Sickle cell anemia is an inherited, lifelong disease.
What Causes Sickle Cell Anemia?
Sickle cell anemia is an inherited disease. People who have the disease inherit two genes for sickle hemoglobin—one from each parent.
People who have the disease are born with it. They inherit two genes for sickle hemoglobin—one from each parent.
People who have sickle cell trait don't have the disease, but can still pass the sickle hemoglobin gene to their children.
In the United States, it's estimated that sickle cell anemia affects 70,000–100,000 people, mainly African Americans. The disease occurs in about 1 out of every 500 African American births. Sickle cell anemia also affects Hispanic Americans. The disease occurs in more than 1 out of every 36,000 Hispanic American births.
More than 2 million Americans have sickle cell trait. The condition occurs in about 1 in 12 African Americans.
What Are the Signs and Symptoms of Sickle Cell Anemia?
Some people have mild symptoms. Others have very severe symptoms and often are hospitalized for treatment.
Many infants don't show any signs until after 4 months of age.
The most common signs and symptoms are linked to anemia and pain.
Signs and Symptoms Related to Anemia
- fatigue
- Shortness of breath
- Dizziness
- Headaches
- Cold hands and feet
- Paler than normal skin or mucous membranes
- Jaundice (a yellowish color of the skin or whites of the eyes)
Signs and Symptoms Related to Pain
Sudden pain throughout the body is a common symptom of sickle cell anemia. This pain is called a sickle cell crisis. Sickle cell crises often affect the bones, lungs, abdomen, and joints.
These crises occur when sickled red blood cells block blood flow to the limbs and organs. This can cause pain and organ damage.
The pain from sickle cell anemia can be acute or chronic, but acute pain is more common. Acute pain is sudden and can range from mild to very severe. The pain usually lasts from hours to as long as a week or more.
Many people who have sickle cell anemia also have chronic pain, especially in their bones. Chronic pain often lasts for weeks or months and can be hard to bear and mentally draining. Most people who have sickle cell anemia have painful crises at some point in their lives. Some have these crises less than once a year. Others may have crises once a month or more. Repeated crises can damage (more likely to adults) the bones, kidneys, lungs, eyes, heart, and liver.
Many factors can play a role in sickle cell crises. Often, more than one factor is involved and the exact cause isn't known.
You can control some factors. For example, the risk of a sickle cell crisis increases if you're dehydrated (your body doesn't have enough fluids). Drinking plenty of fluids can lower the risk of a painful crisis.
You can't control other factors, such as infections.
Painful crises are the leading cause of emergency room visits and hospital stays for people who have sickle cell anemia.
Diagnosis
A simple blood test, done at any time during a person's lifespan, can detect whether he or she has sickle hemoglobin. However, early diagnosis is very important.In the United States, all States mandate testing for sickle cell anemia as part of their newborn screening programs.
If the test shows some sickle hemoglobin, a second blood test is done to confirm the diagnosis.
Doctors also can diagnose sickle cell disease before birth. This is done using a sample of amniotic fluid or tissue taken from the placenta.
Testing before birth can be done as early as 10 weeks into the pregnancy. This testing looks for the sickle hemoglobin gene, rather than the abnormal hemoglobin that the gene makes.
Treatment
Sickle cell anemia has no widely available cure. However, treatments can help relieve symptoms and treat complications. The goals of treating sickle cell anemia are to relieve pain; prevent infections, organ damage, and strokes; and control complications (if they occur). Blood and marrow stem cell transplants may offer a cure for a small number of people who have sickle cell anemia.New Treatments
Research on blood and marrow stem cell transplants, gene therapy, and new medicines for sickle cell anemia is ongoing. The hope is that these studies will provide better treatments for the disease. Researchers also are looking for a way to predict the severity of the disease.Blood and Marrow Stem Cell Transplant
This treatment may offer a cure for a small number of people.The stem cells used for a transplant must come from a closely matched donor.
The transplant process is risky and can lead to serious side effects or even death. However, new transplant approaches may improve treatment for people who have sickle cell anemia and involve less risk.
These transplants are usually used for young patients who have severe sickle cell anemia. However, the decision to give this treatment is made on a case-by-case basis.
Researchers continue to look for sources of bone marrow stem cells—like, blood from babies' umbilical cords. They also continue to look for ways to reduce the risks of this procedure.
Gene Therapy
Gene therapy is being studied as a possible treatment for sickle cell anemia. Researchers want to know whether a normal gene can be put into the bone marrow stem cells of a person who has sickle cell anemia. This would cause the body to make normal red blood cells.Researchers also are studying whether they can "turn off" the sickle hemoglobin gene or "turn on" a gene that makes red blood cells behave normally.
Prevention
You can’t prevent sickle cell anemia, because it’s an inherited disease. If a person is born with it, steps should be taken to reduce complications.
People who are at high risk of having a child with sickle cell anemia and are planning to have children may want to consider genetic counseling.
Living With Sickle Cell Anemia
With good health care, many people who have sickle cell anemia can live productive lives. They also can have reasonably good health much of the time and live longer today than in the past. Many people who have sickle cell anemia now live into their forties or fifties, or longer.If you have sickle cell anemia, it's important to:
- Adopt or maintain a healthy lifestyle
- Take steps to prevent and control complications
- Learn ways to cope with pain
Follow a healthy diet including a variety of vegetables, fruits, whole grains, fat-free or low-fat dairy products, and protein foods.
A healthy diet is low in sodium, sugars, solid fats, and refined grains.
- take folic acid (a vitamin) every day to help your body make new red blood cells.
- drink at least 8 glasses of water every day, especially in warm weather.(to prevent dehydration)
- regular physical activity(avoid activity that makes you very tired)
- get enough sleep and rest. Sleep apnea is a common disorder in which you have one or more pauses in breathing or shallow breaths while you sleep.
- avoid smoking and second hand smoke
