A greenish yellow nose is usually caused by a bacterial infection secondary to a common cold or influenza. Cold is a type of upper respiratory tract infection. The common cold is mainly caused by infections such as rhinovirus, adenovirus and coronavirus, and clinically manifests itself in symptoms such as runny nose, nasal congestion, cough and sore throat. Influenza is mainly caused by influenza virus infection, mainly with fever, fatigue, limb aches and pains and other systemic symptoms, but also may have runny nose, nasal congestion and other symptoms. Whether the runny nose is caused by the common cold or influenza, it is usually clear watery nose or white sticky nose. When the cold is secondary to bacterial infections such as hemolytic streptococcus, staphylococcus aureus, etc., the phenomenon of greenish-yellow nasal mucus will occur. Antibiotics such as amoxicillin and cefixime are needed if the symptoms of a greenish-yellow nose are present. If the symptoms do not improve or worsen, it is recommended to consult a doctor as soon as possible to clarify the cause of the disease and standardize the treatment under the guidance of the doctor to ensure a good prognosis.