Three-year-old baby often cold and runny nose, accompanied by the phenomenon of cough, consider repeated upper respiratory tract infections, primary immunodeficiency diseases and other factors related to the anti-infective treatment, immune reconstruction and other ways to alleviate. 1. recurrent upper respiratory tract infections: three-year-old babies are still relatively young, at this time may be due to the rain and cold and other factors caused by low immunity, which in bacteria, viruses and other pathogens invasion, recurrent upper respiratory tract infections. If you consider the possibility of viral infections, you can follow the doctor’s instructions to be sea saline nasal spray, sputum suction, buspirone anti-inflammatory oral solution and other symptomatic supportive treatment. If you consider bacterial infection, you can cooperate with the doctor to choose amoxicillin, cefuroxime and other drugs anti-infection treatment. 2. Primary immunodeficiency disease: If the three-year-old baby has primary immunodeficiency disease, it may also cause the recurrence of the above symptoms, you can improve the complement and other related tests, and if necessary, you can improve the genetic examination, a clear diagnosis and then according to the cause of the disease for treatment. If the X chain without gammaglobulinemia can be prescribed by the doctor to be gammaglobulin replacement therapy. For the three-year-old baby often cold runny nose symptoms, should be early for standardized treatment, so as to reduce the adverse effects of the disease.