There are three main reasons for runny nose during the recovery period of pneumonia: i. The bacteria in the body are not completely clear, and bacteria enter the nasal cavity of the upper respiratory tract through the blood, thus causing acute rhinitis, with congestion, edema and increased secretion of the nasal mucosa, resulting in symptoms of runny nose. Second, the existence of allergic rhinitis itself, contact with allergic substances during the recovery period of pneumonia, resulting in an acute attack of allergic rhinitis, causing the symptoms of runny nose. Third, within the recovery period of pneumonia by the invasion of viruses, there is an acute upper respiratory tract infection, which is the common cold. The virus multiplies in the nasal cavity of the upper respiratory tract, causing congestion and edema of the nasal mucosa and increased secretion of glands in the nasal cavity, resulting in the symptoms of runny nose. When recovering from pneumonia with runny nose, you can use antihistamines to relieve the symptoms of runny nose, actively find the cause and then take targeted treatment measures.