3-month-old infants cough need symptomatic treatment, may be related to bacterial infection, viral infection, allergies and other factors, the treatment is mainly based on general treatment and medication, specific analysis is as follows: 1. Bacterial infections: infants who cough may be bacterial infections caused by bronchitis or upper respiratory tract infections and other symptoms, you can use the relevant antibiotics, such as amoxicillin and so on. 2. Viral infections: Coughs caused by viral infections can usually heal on their own without special treatment, usually viral infections can be recovered in 3 to 5 days, and coughing symptoms may last for 2 weeks or even a month. 3. Allergic cough: If the cough is caused by allergic factors, you need to check the allergens that cause the baby’s allergy, and generally stay away from the allergens and the cough will get better. At the same time, infants need to pay attention to keep warm, the above drugs are recommended to be taken under the guidance of a doctor, not self-medication.