Key player in the deadly drama of sickle cell disease.

African tribes gave sickle disease names with repeating syllables, perhaps to signify the repeated episodes of pain most sufferers experience.

In the West, Dr. James B. Herrick first described the disease. In 1910, upon microscopic examination of the blood of a West Indian patient, he noticed that the man’s red blood cells (also called erythrocytes) were unusual — they were shaped like sickles. However, only 50 years later, doctors began to understand it.

The red blood cell is the key player in the deadly drama of sickle cell disease. The cell’s main function is to transport oxygen from the lungs to all the other parts of the body.

The shape of a red blood cell affects its lifespan, its movement through blood vessels, and its ability to transport oxygen. Normal red blood cells are round and flexible because they are filled with watery liquid, which can be easily compressed.

This flexibility enables normal red blood cells to navigate through the narrow blood vessels, delivering oxygen to every part of the body. Red cells are able to carry oxygen because of haemoglobin, which holds on to the oxygen. Normal haemoglobin, (HbA) remains dissolved inside the red blood cell.

The haemoglobin inside the red blood cells of sickle cell patients is abnormal (HbS). Unlike HbA, under certain conditions, HbS can come out of solution, and form crystals — brittle and incompressible and the cell loses its flexibility.

The strands of crystals also force the cell to twist into abnormal shapes. These stiff, abnormally shaped sickle cells can clog blood vessels, cutting off circulation, so oxygen doesn’t get delivered to organs beyond the blockage. If blood flow is not restored quickly, tissue damage can occur.

When oxygen supply is cut off from a particular part of the body, it produces pain. Lack of oxygen or low oxygen levels is responsible for pain and the other effects of sickle cell disease.