Spitting bubbles is a behavior that often occurs in small babies, adults generally do not appear, so the main description of small babies spitting bubbles. The parents usually can’t identify whether the bubble is normal or caused by pneumonia based on the symptom of spitting bubbles alone, and need to combine with other symptoms of the baby for a comprehensive analysis. 1, simple spitting bubbles: because the baby’s mouth is relatively shallow, swallowing function is not well developed, lip closure and swallowing movements are not coordinated, will not regulate the excess saliva in the mouth, so it is easy to drool and spit bubbles. If a baby’s bubble vomiting is caused by pneumonia, it is usually accompanied by other symptoms, such as faster breathing rate, faster heartbeat, and also fever, poor spirits, and refusal of milk. In severe cases, there may be varying degrees of cyanosis of the lips and mouth, which is caused by pneumonia leading to lack of oxygen in the body. Parents can take their babies to the hospital for routine blood tests, Mycoplasma pneumoniae and other related tests, and if the diagnosis is confirmed, active medication is needed.