Coughing up white sputum is mainly caused by viral infections, allergies, and some bacterial infections, while yellow sputum is mainly caused by bacterial infections.
Coughing up white sputum is due to viral invasion of the respiratory tract resulting in increased mucosal secretion, producing white sputum. Mostly seen in upper respiratory tract diseases caused by viral infections, common viruses are respiratory syncytial virus, influenza virus and so on. It can also be seen in allergic diseases and some patients with bacterial infections.
Coughing up yellow sputum is mainly due to the bacterial discharge of toxins damage to the mucosal cells, sputum formation accompanied by pus cells caused. It is common in upper respiratory tract diseases caused by bacterial infections, and common pathogens such as Staphylococcus aureus, Streptococcus pneumoniae, Klebsiella, and so on.
Whether coughing white sputum or yellow sputum, it is recommended to consult a doctor and take active treatment under the guidance of a physician.