Nearly half of your blood's volume is red blood cells

Red blood cells play an incredibly important role in our bodies. They carry oxygen to our organs and muscles and remove carbon dioxide from our system through arteries and veins, which make up the blood vessel system in all mammals. In order for our bodies to function properly, we need a ton of red blood cells. There are roughly 20-30 trillion red blood cells in the average human, which makes up approximately 40-45% of our blood's volume