If a three-year-old baby has recurrent colds and coughs, consider the following situations: First, the pathogens such as viruses and bacteria that the child is infected with have not been completely removed, forming chronic lesions that appear after each time the baby gets cold or other triggers for reinfection. Second, the child may have relatively low resistance and immunity, poor clearance of pathogens, and relatively poor sensitivity to drugs, and will be prone to recurrent colds and coughs. Third, we should pay attention to the presence of chronic underlying respiratory diseases in children, such as those with chronic rhinitis, sinusitis, chronic laryngitis, such as those with mycoplasma infections, which are prone to recurrent colds and coughs. Fourth, some children may have poor nutritional status, malnutrition and poor digestion, which may also easily lead to recurrent colds and coughs.