The first thing you need to do is to quit smoking, and the second thing you can do is to combine the expectorant medication. 1. Quit smoking: the most important cause of phlegm viscosity is smoking, especially the amount of smoking is relatively large crowd, but also on the lung trachea, bronchial mucosa and other damage, local inflammatory response, resulting in secretion generation. 2. Drugs: Commonly used drugs include Ambroxol, acetylcysteine, etc., to help sputum dilution. The choice of specific drugs also need to consult a doctor in time, according to the doctor’s instructions for use.