I actually went to my primary while my blue line was showing around my lips. My O2 levels are always perfect. He told me our lips start to fade as we age and the blue look could be from being warm or cold, etc., but not to worry. I was sure it was congestive heart failure (had just had a perfect EKG when I had a colonoscopy). He told me I'd have LOADS of other symptoms before the blue lines and the whole lips would be blue. The next week I went in because I thought my fingernail beds were blue. Felt pretty stupid when he showed me HIS hands. His were very blue. It was cold outside and their heater had broken, so it was cold in the bldg. He told me to put on lipstick if I couldn't stop looking in the mirror and to take an anxiety pill!