3 months old baby cold and cough, because the age is too small, poor resistance, immature organ function development is easy to aggravate, so should be timely treatment, usually pay attention to do the following points: First, symptomatic treatment, you can give the baby to take cough and phlegm class of Chinese medicine or Western medicine class. Second, most of the cold is a respiratory viral infection, you can anti-viral treatment, such as giving the baby oral anti-viral oral solution, with interferon spray or ribavirin spray, local spray throat anti-viral treatment. Third, to do a good job of diet management, cold and cough during the digestive and absorption function is reduced, prone to gastrointestinal symptoms, so you should feed a small number of meals, breastfeeding mothers should pay attention to avoid greasy and irritating food intake. Fourth, closely observe the changes in the condition. Once the cough worsens, there is recurrent high fever or poor mental health, you should promptly see the pediatric emergency room or pediatric outpatient clinic.