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What is Sickle Cell Disease?

Sickle cell disease (SCD) is an inherited blood disorder that affects the red blood cells. Normally, red blood cells are round and flexible, allowing them to move easily through blood vessels and carry oxygen throughout the body. In individuals with sickle cell disease, the red blood cells become hard, sticky, and shaped like a crescent or “sickle.”

These sickled cells can block blood flow, causing severe pain episodes known as crises, as well as complications such as infections, anemia, stroke, organ damage, and fatigue. Because the cells break down faster than normal red blood cells, the body cannot make enough healthy cells to carry oxygen properly.

Sickle cell disease is inherited when a child receives a sickle cell gene from both parents. Individuals who carry only one gene are said to have the “sickle cell trait” and may not have symptoms, but they can pass the gene to their children.

Although there are currently no universal cure, treatments, medications, and supportive care help many individuals manage the disease and live full lives. Early education, awareness, and access to resources are essential for improving outcomes and supporting warrior families.

Types of Sickle Cell Disease

There are several types of sickle cell disease, each defined by the specific genetic mutations:

1. Hemoglobin SS Disease (HbSS)

Most common and severe form of SCD.
Occurs when a person inherits two sickle cell genes (one from each parent).
Individuals with HbSS typically experience the most severe symptoms and complications.

2. Hemoglobin SC Disease (HbSC)

Caused by inheriting one sickle cell gene and one gene for another abnormal hemoglobin called hemoglobin C.
Symptoms are generally milder than HbSS, but complications can still occur.

3. Hemoglobin Sβ⁰ Thalassemia (HbSβ⁰)

Results from inheriting one sickle cell gene and one gene for beta-zero thalassemia (a condition that reduces or eliminates the production of normal beta-globin).
Symptoms are similar to HbSS and can be severe.

4. Hemoglobin Sβ⁺ Thalassemia (HbSβ⁺)

Involves one sickle cell gene and one gene for beta-plus thalassemia (which allows some normal hemoglobin production).
Symptoms are usually milder than HbSS or HbSβ⁰.

5. Other Rare Types

There are additional, less common forms of SCD that result from other combinations of abnormal hemoglobin genes, such as hemoglobin SD, hemoglobin SE, and hemoglobin SO-Arab.
The severity of symptoms varies depending on the specific genetic combination.