The rank of blood cells in a normal person and one with polycythemia is the same. how can you conclude that the person has polycythemia?

Polycythemia is defined an abnormal increase in the number of circulating red blood cells. It is mainly caused by a cancerous condition known as myeloproliferative disorder or due to a low supply of oxygen to body tissues usually due to living in high altitude areas and the body tries to compensate by producing more red blood cells to increase oxygen carrying capacity of the blood Normal blood count values in a male adult is 4.7 to 6.1 million cells/mcL, while in a female adult it is 4.2 to 5.4 million cell/mcL. If this blood cell count is significantly higher then these values, and remains there or continues to rise, over a given period of time, accompanied with some specific symptoms, then polycythemia is suspected.