Human blood was first classified into four types in the first decade of the 1900s by Austrian physician Karl Landsteiner. Many studies have suggested that blood type characteristics can also affect a person’s health and personality. The following article will discuss blood type O in more detail.

The Rhesus (Rh) factor is an inherited protein found on the surface of red blood cells. If your blood has this protein, it is considered Rh positive, and if it does not, it is Rh negative.

While most human blood is made up of the same basic components, scientists have discovered that there are many different types of blood. There are eight different blood types, and these are determined by the genes you inherit from your parents.