Polycythemia Vera PV and relative polycythemias incl stress hemoconcentration 

Relative polycythemias incl stress hemoconcentration (stress-hemoconcentration)

Second, and more commonly, hemoconcentration occurs when the number of red blood cells remains constant while plasma volume decreases. This condition has been variously referred to as ‘stress’ polycythemia, relative polycythemia, pseudopolycythemia, spurious polycythemia, or stress-hemoconcentration.