Three and a half year old baby runny nose, nasal congestion, cough, consider colds, allergies and other causes, common treatment modalities are medication, general treatment and so on. 1. Colds: If caused by viruses, generally no special medication is needed. If combined with bacterial infection, should follow the doctor to use cefixime, amoxicillin and other antibacterial drugs. Runny nose, cough itself is the body in the discharge of germs in the body, daily through hot compresses, saline nasal cleaning, taking honey or hot pear soup to ease the discomfort. 2. Allergy: caused by contact, inhalation of allergic substances, in most cases away from the allergen symptoms can be relieved. If the allergy is serious, you can take oral antihistamine drugs, such as cetirizine. Three and a half year old baby runny nose, nasal congestion, cough, there may be other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, give targeted treatment or treatment. All of the above medications should be used under the guidance of a doctor, avoid self-medication.