I often have a pale blue-ish line around my lips, particularly the bottom one. Some times are more noticeable than others. I've looked it up on google and everything to do with blue lips sounds so severe! I have asthma that's controlled and never have 'attacks'. Whenever I've had one of those oxygen monitors stuck on my finger at the GP's, it's always good. My partner and a friend have both commented on it.
Personally, I'm not that concerned, though it's not a good look. But thought I'd ask the wise peeps of mumsnet in case other people can tell me they have this too and either reassure me or tell me I've got something dreadful that's too rare even for t'interweb to know about it.