an abnormal condition of blue discoloration is called
0. Cyanosis is the abnormal blue discoloration of the skin and mucous membranes, caused by an increase in the deoxygenated haemoglobin level to above 5 g/dL.. Cyanosis is the abnormal blue discoloration of the skin and mucous membranes, caused by an increase in the deoxygenated haemoglobin level to above 5 g/dL.