The main role of red blood cells is to transport oxygen throughout the body. These cells, also known as erythrocytes, contain hemoglobin, a protein that binds oxygen in the lungs and carries it to tissues and organs. Red blood cells also play a role in transporting carbon dioxide, a waste product produced by cells, back to the lungs for exhalation. Their unique biconcave shape increases the surface area for gas exchange and enables flexibility while navigating through blood vessels. Maintaining a healthy red blood cell count is crucial for overall health and efficient bodily functions.