My newborn have very noisy breathing when he is asleep lying down. Will he get choke by the mucus in his nose?

You can use Sterimar Nasal Spray, which is safe to clear baby's nose. If he/she has mucus, you can use NoseFrida to clear it. If your baby is prone to having runny nose try to let baby to sleep in non-aircon room at night.

Maybe you can try running a humidifier in your baby’s room while they sleep to help loosen mucus. Or using nasal saline drops; putting one or two drops of saline in the nose can help loosen mucus.

thanks