Most people have seen their own blood or the blood of others many times, but few know what blood is really made of. An adult has around 5-6 liters of it. It distributes oxygen, nutrients and has other useful functions throughout the body. Blood is 55% plasma and the remaining 45% is formed elements. Below you can see a visualization from Visual Capitalist that shows the composition of blood in detail.

Blood composition

Abnormal Red Blood Cells

Normal red blood cells are round, flattened disks that are thinner in the middle. What does blood look like in various diseases?

Source: https://www.visualcapitalist.com/visualizing-the-composition-of-blood/