If the sputum is clear and white and sticky, it is usually considered to be caused by chronic pharyngitis and is mostly accompanied by foreign body sensation in the throat. If the sputum changes with the change of seasons, when it is cold, the sputum is more often considered to be caused by chronic bronchitis. Bronchiectasis patients have a lot of sputum, and the sputum has the characteristic of stratification, and may be accompanied by the phenomenon of blood in the sputum, and lung abscess patients have fishy sputum that may be accompanied by fever.