Why Does the Skin Pigment and Finger Nails Turn Blue?
When the unoxygenated hemoglobin (also known as reduced hemoglobin) levels in the capillaries exceed 5 g/dL, the skin pigment, the mucousal membranes the finger nail beds, and in some cases, even feet, ears, and nose turn blue. It must be noted, however, that the bluish skin pigment tinge in itself is not the disease, it is often the most visible sign of low blood oxygen saturation levels -Cyanosis. In many cases, cyanosis is quite obvious when blood oxygen satuation levels fall below 90%. It is also important to note that many anemic patients do not show any visible signs of cyanosis even when they are hypoxemic.