Sickle cell disease is a blood condition that is passed down in families. It affects hemoglobin, a part of red blood cells that carries oxygen through the body. In people with sickle cell disease, some red blood cells can become hard, sticky, and shaped like a crescent instead of being round and flexible.

These cells may break apart too soon. This can cause the body to have too few red blood cells, which is called anemia. The cells can also get stuck in small blood vessels and block the flow of blood and oxygen. These blockages can cause sudden, severe pain. Sickle cell disease may also cause tiredness, infections, stroke, or damage to organs over time.

The signs and effects can be different for each person. Regular care from a healthcare team can help manage symptoms and lower the chance of serious health problems.

Hemophilia is a rare bleeding condition. It happens when the blood does not clot the way it should. The blood uses proteins called clotting factors to help stop bleeding. People with hemophilia do not have enough of certain clotting factors, so bleeding may last longer.

Most people with hemophilia are born with it. It is often passed down in families and is more common in males, but females can also have hemophilia or have symptoms. About 1 out of 3 babies diagnosed with hemophilia have no known family history of the condition.

People with hemophilia may bleed longer than expected. Bleeding can also happen inside the body, including in the joints. Treatment depends on the type and how serious the condition is. Treatment may be used to stop bleeding or given regularly to help prevent it.