A cough does not always go from no sputum to sputum, but it is also possible to have a cough without sputum from the beginning to the end, or to have a cough with sputum from the beginning. The amount of sputum is not related to the severity of the disease or whether the disease has improved. Cough without sputum is most often seen in mycoplasma bronchitis or pneumonia with mycoplasma infection, and cough with sputum is seen in patients with bronchiectasis, emphysema, lung abscess, and pneumonia. In Chinese medicine, coughing without phlegm is mostly considered as Yin deficiency dry cough, while coughing with phlegm is usually considered as Spleen deficiency, phlegm-dampness or wind-cold cough.