No cough but phlegm may be caused by environmental irritation, pharyngitis, lung infection, etc. It can be treated by reducing irritation, promoting phlegm expulsion, and fighting infection. 1. Reduce irritation: no cough but phlegm may be caused by smoking or environmental factors, which can be relieved by quitting smoking, wearing a mask and drinking more water. 2. Promote phlegm expulsion: medicines such as Ambroxol and acetylcysteine can be used to dilute phlegm and promote phlegm expulsion as prescribed by the doctor. If infants and young children do not know how to expel phlegm, parents can use empty palms to pat their backs from bottom to top to assist in the expulsion of phlegm. 3. Anti-infective treatment: no cough but sputum may also be caused by lung infection, should be examined and evaluated by a doctor, follow the doctor’s instructions to use amoxicillin, azithromycin and other antibiotic treatment. If you do not cough but have sputum, you should consult a doctor in time and choose the appropriate treatment after examination and evaluation by a doctor to avoid delaying your condition.