For the symptoms of cough and runny nose in three-month-old babies, the following measures can be applied to deal with them. Firstly, mephentermine ammonium can be applied, whose ingredients mainly include chlorpheniramine maleate, etc., which can play a good role in improving the runny nose. Secondly, as children suffer from symptoms caused by acute rhinitis, they need to be treated with montelukast, loratadine and so on. In addition, massage can be applied to deal with it, you can press and rub the nasal pass point. The nasal passage point is located at the junction of the nasal wing and nasal cartilage in children, so you can use your thumb to press and rub the nasal passage point in children, which can also have the effect of relieving nasal congestion and cough.