Coughing up yellow sputum can be caused by a number of things and is not necessarily a new type of pneumonia. Many respiratory diseases can cause yellow sputum: 1. Bacterial cold: when the body due to cold and other factors such as resistance to decline, vulnerable to pathogenic bacteria invasion, sore throat, fever, runny, cough, cough and other symptoms, this time may cough up yellow phlegm. 2. Bronchitis: When Staphylococcus aureus or Streptococcus pneumoniae infects the respiratory tract, leading to bronchitis, coughing and sputum symptoms can occur. 3. Lung cysts: Lung cysts are often complicated by lung infections, resulting in symptoms such as chest tightness, dyspnea, cough and sputum. 4. New type of pneumonia: New type of pneumonia has ten main symptoms: fever, dry cough, fatigue, sore throat, decreased sense of smell (taste), nasal congestion, runny nose, conjunctivitis, muscle aches and diarrhea, while the specific symptoms and characteristics vary from person to person. In the case of cough with yellow sputum, it is recommended to seek immediate medical attention, and according to the results of the examination, treatment and medication under the guidance of a specialized doctor.