Learn about the symptoms, causes and treatment of this inherited blood disorder that, in the United States, is more common among Black people.
Sickle cell anemia is one of a group of inherited disorders known as sickle cell disease. It affects the shape of red blood cells, which carry oxygen to all parts of the body.
Red blood cells are usually round and flexible, so they move easily through blood vessels. In sickle cell anemia, some red blood cells are shaped like sickles or crescent moons. These sickle cells also become rigid and sticky, which can slow or block blood flow.
The current approach to treatment is to relieve pain and help prevent complications of the disease. However, newer treatments may cure people of the disease.
Symptoms of sickle cell anemia usually appear around 6 months of age. They vary from person to person and may change over time. Symptoms can include:
Episodes of pain. Periodic episodes of extreme pain, called pain crises, are a major symptom of sickle cell anemia. Pain develops when sickle-shaped red blood cells block blood flow through tiny blood vessels to the chest, abdomen and joints.
The pain varies in intensity and can last for a few hours to a few days. Some people have only a few pain crises a year. Others have a dozen or more a year. A severe pain crisis requires a hospital stay.
Some people with sickle cell anemia also have chronic pain from bone and joint damage, ulcers, and other causes.
See your healthcare professional right away if you or your child has symptoms of sickle cell anemia, including fever or stroke.
Infections often start with a fever and can be life-threatening. Because children with sickle cell anemia are prone to infections, seek prompt medical attention for a fever greater than 101.5 degrees Fahrenheit (38.5 degrees Celsius).
Seek emergency care for symptoms of stroke, which include:
Sickle cell anemia is caused by a change in the gene that tells the body to make hemoglobin. Hemoglobin is the iron-rich compound in red blood cells that allows these cells to carry oxygen from the lungs to the rest of the body. The hemoglobin associated with sickle cell anemia causes red blood cells to become rigid, sticky and misshapen.
For a child to have sickle cell anemia, both parents must carry one copy of the sickle cell gene and pass both copies to the child.
If only one parent passes the sickle cell gene to the child, that child will have the sickle cell trait. With one typical hemoglobin gene and one sickle cell gene, people with the sickle cell trait make both typical hemoglobin and sickle cell hemoglobin.
Their blood might contain some sickle cells, but they generally don't have symptoms. They're carriers of the disease. That means they can pass the gene to their children.
For a baby to have sickle cell anemia, both parents must carry a sickle cell gene. In the United States, sickle cell anemia most commonly affects people of African, Mediterranean and Middle Eastern descent.
Sickle cell anemia can lead to a host of complications, including:
If you carry the sickle cell trait, it can help to see a genetic counselor before you get pregnant. A counselor can help you understand your risk of having a child with sickle cell anemia. You also can learn about possible treatments, preventive measures and reproductive options.
A blood test can check for the form of hemoglobin that underlies sickle cell anemia. In the United States, this blood test is part of routine newborn screening. But older children and adults can get the test too.
In adults, a blood sample is taken from a vein in the arm. In young children and babies, the blood sample is usually collected from a finger or heel. The sample then goes to a laboratory to be screened for the sickle cell form of hemoglobin.
If you or your child has sickle cell anemia, your healthcare professional might suggest other tests to check for possible complications of the disease.
If you or your child carries the sickle cell gene, you'll likely be referred to a genetic counselor.
A special ultrasound machine can reveal stroke risk in children. The test uses sound waves to measure blood flow to the brain. This painless test can be used in children as young as 2 years old. Regular blood transfusions can decrease stroke risk.
Sickle cell disease can be diagnosed in an unborn baby by sampling some of the amniotic fluid surrounding the baby in the womb. If you or your partner has sickle cell anemia or the sickle cell trait, ask your healthcare team about this screening.
Management of sickle cell anemia is usually aimed at avoiding pain episodes, relieving symptoms and preventing complications. Treatments might include medicines and blood transfusions. For some children and teenagers, a stem cell transplant might cure the disease. Gene therapies also are being developed that may offer cures for people with sickle cell disease.
Children with sickle cell anemia might receive penicillin from about 2 months old to 5 years old, or longer. This medicine can help prevent infections, such as pneumonia, which can be life-threatening to children with sickle cell anemia.
Adults who have sickle cell anemia might need to take penicillin throughout their lives if they've had pneumonia or surgery to remove the spleen.
Childhood vaccinations are important for preventing disease in all children. Vaccinations are even more important for children with sickle cell anemia because their infections can be severe.
Your child's healthcare team should make sure that your child gets all the recommended childhood vaccinations. These include vaccines against pneumonia, meningitis, hepatitis B and a yearly flu shot. Vaccines also are important for adults with sickle cell anemia.
During global health threats, such as the COVID-19 pandemic, people with sickle cell anemia should take extra precautions. These include staying at home as much as possible and for those who are eligible, getting vaccinated.
Blood transfusions. Red blood cell transfusions are used to treat and prevent complications, such as stroke, in people with sickle cell disease.
In this procedure red blood cells are removed from a supply of donated blood, then given through a vein to a person with sickle cell anemia. This increases the number of red blood cells that are not affected by sickle cell anemia. This helps reduce symptoms and complications.
Risks include an immune response to the donor blood, which can make it hard to find future donors. Infection and excess iron buildup in the body are other risks. Because excess iron can damage your heart, liver and other organs, you might need treatment to reduce iron levels if you undergo regular transfusions.
Stem cell transplant. This also is known as a bone marrow transplant. The procedure involves replacing bone marrow affected by sickle cell anemia with bone marrow from a donor. The procedure usually uses a matched donor, such as a sibling, who doesn't have sickle cell anemia.
A stem cell transplant can cure sickle cell anemia. Stem cell transplant is recommended only for people, usually children, who have significant symptoms and complications of sickle cell anemia. The risks associated with the procedure are high and include death.
Stem cell gene addition therapy. In this treatment option, the person's own stem cells are removed, and a gene to produce typical hemoglobin is injected. The stem cells are then given back to the person in a process known as autologous transplant. This option may be a cure for people with sickle cell disease who do not have a well-matched donor.
Gene editing therapy. This Food and Drug Administration (FDA)-approved treatment works by making changes to the DNA in a person's stem cells. Stem cells are removed from the body, and the sickle gene is changed, also called edited, to help restore the cells' ability to make healthy red blood cells. The treated stem cells are then returned to the body through the blood. This is called an infusion.
People who are successfully treated with gene editing therapy no longer have symptoms of sickle cell disease. This treatment is FDA-approved for people 12 years old and older. Long-term effects of this new treatment are not yet known and will continue to be studied.
Clinical trials are ongoing to address stem cell transplantation in adults and gene therapies.
The following steps to stay healthy might help you avoid complications of sickle cell anemia:
If you or someone in your family has sickle cell anemia, these ideas might help you cope:
Sickle cell anemia is usually diagnosed through genetic screening done when a baby is born. Those test results will likely be given to your primary healthcare professional, who may refer you to a doctor who specializes in blood disorders, called a hematologist, or a pediatric hematologist.
Here's information to help you get ready for your appointment.
Make a list of:
Bring a family member or friend along, if possible, to help you remember the information you're given.
For sickle cell anemia, questions to ask your healthcare professional include:
Don't hesitate to ask other questions.
Your healthcare professional is likely to ask you questions, including: