What is Sickle Cell

What is Sickle Cell

What is it?

Sickle Cell is a group of inherited red blood cell disorders. It is passed down the same way people get the color of their eyes, skin, and hair from their parents. Both parents need to carry a gene for Sickle Cell in order for a child to inherit the disease. There is absolutely no way to catch the disease. You’re either born with it or you’re not.

Circulatory system illustration

What’s happening in the body?

Healthy red blood cells are smooth, bendable, and round so they can move easily through small blood vessels and carry oxygen to every part of the body. For someone with Sickle Cell, the red blood cells become stiff, sticky, and shaped like crescent moons, or “sickles.” These sickled cells are more fragile and break down more easily. As a result there may not be enough oxygen delivered to the body.

Why am I so much more tired than other people?

You’re tired because your blood does not carry enough oxygen throughout your body. A healthy blood cell will live for about 120 days, but a sickle cell only lives for 10-20 days. Because sickle cells are very fragile, they tend to become damaged and die sooner. As a result, someone with Sickle Cell usually doesn’t have the normal amount of red blood cells in their body. This is called anemia. It happens because their body can’t make enough new red blood cells when cells are dying quickly. It also means that their body isn’t getting enough oxygen to their tissues and organs. This can make someone feel very tired.

When a person who does not have Sickle Cell runs, they get out of breath because their body can’t deliver enough oxygen to their muscles. In comparison, a person with Sickle Cell can get this tired just from doing everyday activities. They get fatigued because their blood does not deliver enough oxygen directly to their tissues. Breathing more oxygen is not the solution, but getting treatment for Sickle Cell may help.

Red and sickle blood cell illustrations

What causes Sickle Cell pain?

Sickle Cell pain is caused when sickled blood cells get stuck in blood vessels. Because of their shape, stiffness, and stickiness, sickled cells won’t always slide past each other smoothly like round red blood cells do. Instead, they can catch on each other and form pile ups. These pile ups mean that your organs and bones may not be getting the oxygen that they need.

Who has Sickle Cell and why?

About 100,000 people in the United States have Sickle Cell. People of African descent make up 90% of the population with Sickle Cell in the United States. However, it also affects people of Hispanic, South Asian, Southern European, and Middle Eastern ancestry. Sickle Cell affects people whose ancestors came from parts of the world where malaria is common. Sickle Cell can affect these populations because having the Sickle Cell Trait helps protect a person from the harmful effects of malaria. Sickle Cell probably comes from evolution’s attempt to protect against one disease, even though it introduced other health risks in the process.

World map with malaria-endemic regions highlighted

What causes the blood cells to form a sickle shape?

Red blood cells contain a protein called hemoglobin. Hemoglobin carries the oxygen that the blood delivers where it is needed throughout the body. In healthy red blood cells, once the hemoglobin has delivered the oxygen, the cell makes its way back to the lungs to pick up more oxygen. In Sickle Cell, the sickle shape forms because the gene for Sickle Cell makes a person’s hemoglobin act differently.

Sickle hemoglobin (hemoglobin S) is not like normal hemoglobin. After hemoglobin S has delivered the oxygen to cells or tissues, the red blood cell has a hard time keeping its shape. The hemoglobin S becomes sticky and forms strands inside the red blood cell. It is these strands (called polymers) that cause the red blood cell to change into the sickle shape. These sickle-shaped cells stick to the blood vessel walls and cannot squeeze through the tiny blood vessels called capillaries. Blood flow through capillaries can slow or stop in many different parts of the body. This deprives tissues and organs of oxygen.

Bloodstream illustrations comparing healthy hemoglobin and sickle cell hemoglobin