So my otherwise healthy 3 year old gets occasional blue lips. As in purple and blue around them. Usually when she's cold.
If it was my baby (with a congenital heart defect - linked to downs syndrome rather than genetic) I would rush her to A&E and fear heart failure/respiratory problems.
But we have no reasons to think she has heart problems. She had her sats taken recently when at doctors for a UTI, sms they were normal range.
She has no other health issues other than mild allergies and a cough that can be persistent and complains of a sore chest when doing lots of exercise. She takes ventolin for these although never diagnosed formally as asthmatic.
I'm reluctant to take her to GP as we're there all the time! And she's otherwise fine.