There are two main reasons why babies vomit when they cough: 1. Because coughing itself causes irritation to the throat, including the coughing action itself, and also the secretions can irritate the throat. Vomiting is caused by the stimulation of the pharynx, which induces a physiological reflex, and when this stimulation is stronger, the child is also more sensitive and will have a vomiting reflex; 2. The reason for intra-abdominal pressure. When a child coughs, the abdomen also helps to do the coughing action, the stomach, intra-abdominal pressure increases, the stomach, esophagus is more likely to reflux, thus the phenomenon of vomiting. Vomiting is not something to worry about because it is not necessarily a bad thing, it can help your child expel phlegm. Children are too young to necessarily cough up sputum on their own. Vomiting is actually a very common way to expel sputum, as long as you make sure your child doesn’t accidentally inhale the vomit, doesn’t develop aspiration pneumonia, and cleans up the vomit in a timely manner. Vomiting itself does not cause much harm to the child, so parents do not need to worry too much.