What is SCD?

Sickle cell disease is a genetic condition caused by unhealthy and abnormal red blood cells. Instead of being soft and round, these red blood cells are hard and sticky, and shaped like a “sickle.” These unhealthy cells clog up blood vessels and reduce good oxygen flow, creating serious problems of intense pain, infections and more.

Healthy Cells

Sickled Cells

How do you get SCD?

It’s an inherited disease – meaning the genes were passed down to you from your parents, at birth. To have SCD, you have either inherited two sickle cell genes, or one sickle cell gene and a different type of “abnormal hemoglobin” gene from your parents. Often, parents aren’t aware that they carry the sickle cell gene or sickle cell trait, and sickle cell disease comes as a bit of a surprise after the baby’s born. Today in the US, screening automatically happens at birth to check for SCD.

SCD runs in families, but SCD is also more common in certain ethnic groups.

Fast Facts:


1 to 3 million

Americans have SCT



is not a disease (but it can still bring complications)


If you have

you inherited the gene from only one of your parents


8 to 10 %

of African Americans have SCT but it also affects other groups — including South Asians, Hispanics, Middle Easterners and Caucasians from southern Europe.

Types of SCD

There are several types of sickle cell disease, although some are more commonly known:

Hemoglobin SS

People who have this form of SCD inherit two sickle cell genes (“S”), one from each parent. This is commonly called sickle cell anemia and is usually the most severe form of the disease.

Hemoglobin SC

People who have this form of SCD inherit a sickle cell gene (“S”) from one parent and from the other parent a gene for an abnormal hemoglobin called “C”. Hemoglobin is a protein that allows red blood cells to carry oxygen to all parts of the body. This is usually a milder form of SCD.

Hemoglobin S beta thalassemia

People who have this form of SCD inherit one sickle cell gene (“S”) from one parent and one gene for beta thalassemia, another type of anemia, from the other parent. There are two types of beta thalassemia: “0” and “+”. Those with HbS beta 0-thalassemia usually have a severe form of SCD. People with HbS beta +-thalassemia tend to have a milder form of SCD.

Hemoglobin SD,
Hemoglobin SE,
and Hemoglobin SO

People who have these forms of SCD inherit one sickle cell gene (“S”) and one gene from an abnormal type of hemoglobin (“D”, “E”, or “O”). Hemoglobin is a protein that allows red blood cells to carry oxygen to all parts of the body. The severity of these rarer types of SCD varies.

Health problems and complications of SCD

Depending on the person and their specific type of SCD, there can be a wide range of health issues that stem from managing the disease. For example, you’ll often hear many warriors say that no two pain crises are alike and it’s hard to even describe how terrible they feel. Keeping in mind that not everyone will experience the exact same issue is key, but some of the biggest issues are:

Pain crises

or pain episodes


(lacking enough healthy red blood cells in the body)


    Other problems that can develop include:

  • Bone or joint damage (like in the hips)
  • Leg ulcers and sores
  • Kidney or urinary problems
  • Eye and vision problems
  • Delayed growth or puberty

Some issues can also turn life-threatening. For example, Acute chest syndrome – whose signs include chest pain, trouble breathing, coughing and fever – needs to be treated immediately at a hospital.

Treatment Options for SCD

Treatments for SCD have come a long way, and we’re grateful for all of the breakthroughs in recent times. Even with these advancements, however, not every treatment is right for every person with sickle cell disease. As every person is different, understanding your body and having the right treatment plan in place is key.

Some current treatments for SCD include:

  • Blood transfusions
  • Folic acid supplements
  • Hydroxyurea
  • L-glutamine (Endari)
  • Oxbryta (Voxelotor)
  • Adakveo (Crizanlizumab)
  • Stem Cell Transplant

Treating SCD can be highly complex and evolves over time as a person ages. To find the right treatment plan, it’s important that patients and care teams work together to address those needs.

Is there a cure?

Today, stem cell transplants (or bone marrow transplants) are the only recognized cure for sickle cell disease. Only a limited number of patients are good candidates to try these transplants, and it has to be cleared by your medical team. If you’d like more information about this, please speak with your doctor.

We are hopeful that one day a more universal cure will exist for the community. Until then, Sick Cells will continue to advocate for new treatments that are affordable and accessible to all.

Learn More About Sickle Cell Disease From These Great Resources:

Approved Treatments

A news organization that provides information on all treatments for SCD to use when discussing treatment options with your physician or other qualified health provider.

SCD Resource Library

Research, stories, and fact sheets from Sickle Cell Disease Coalition for current patients, caregivers, and medical professionals.

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