3Blue Fingernails or Skin
The bluish or purplish discoloration of the skin, which is called, cyanosis is caused by low oxygen saturation. It happens to be one of the early signs of the presence of a cancerous tumor in your lungs.
This color change could occur gradually and keep getting progressively darker over time. Cyanosis is also visible on the lips, fingernail beds, and overall skin on your body when gets more advanced.
