Your child's lips turning black is something serious and worrisome. Please see a paediatrician soonest for proper evaluation and treatment.

It might happen due to a lip licking habit, or your baby may be sucking on their lips. Dehydration and dry weather are also common causes. Sometimes chapped lips may point to underlying health conditions. Dry winter, hot summer months, or too much wind exposure can cause lips to lose moisture.

Never leave children alone as for the swelling please apply ice packs and watch for any reactions.

This is a self comforting habit for your baby, he/she will out grow and stop it with time.

It's a self-comforting habit that your baby will outgrow with time.