It's a complex process that involves several stages and factors:

* Erythropoietin (EPO): A hormone produced primarily by the kidneys that stimulates the production of red blood cells.

* Stem cells: In the bone marrow, specialized stem cells differentiate into red blood cell precursors.

* Maturation stages: These precursors undergo a series of developmental stages, characterized by changes in size, shape, and the production of hemoglobin.

* Release: Once mature, red blood cells are released into the bloodstream where they circulate for approximately 120 days.