Hi, my 18 days baby is suffering from phlegm mucus, he chokes and giggle please assist?

30 degree angle : Continue to feed at a 30 to 45 degree angle with the baby’s head elevated. The baby may have aspiration of secretions and / or reflux. If there are frequent spit ups, a thickener may be added to feeds in a bottle. Check his temperature and report any elevation to your pediatrician.

See his doctor: At his age, it is important to have him checked by his pediatrician. Could be minor reason, some extra mucous or overfeeding or nasal congestion, but there are more serious reasons which are possible, so please have him examined to get the proper medical advice.