1, polluting gas inhalation: such as smoking, long-term inhalation of second-hand smoke, or inhalation of polluting gas containing sulfur dioxide, soot, lime, etc., some of the particles in the gas are directly inhaled into the lungs, which on the one hand damages lung function, and on the other hand causes secondary infection. When tissue exudate and tissue debris accumulate in the alveoli, with coughing and sputum discharge, some of the deposited particles are discharged with the sputum, and small brown jelly-like clots may appear. At this time, we should get out of the polluting environment as soon as possible, and give cefoperazone sodium etc. for anti-infection treatment if necessary, together with drugs such as aminoglutethimide hydrochloride for sputum treatment to promote sputum discharge and deposition of polluting particles; 2. Klebsiella pneumoniae infection: Klebsiella pneumoniae is a bacterium that normally exists in the environment and can also colonize the oral pharynx, which can be mistakenly inhaled with the secretions, and when the body’s immunity is impaired, thus triggering lung infection. A small number of patients can be acquired nosocomially, e.g., after using a nebulizer that has not been properly sterilized, but the onset is often aggregated and may usually lead to severe pulmonary infections with the potential for multi-drug resistance. Typical symptoms are sputum of a brown jelly-like nature, with alcohol abuse as the main trigger, and also fever, chills, cough, and coughing sputum. Patients need to perfect sputum culture to clarify the infecting pathogens, and the general chest X-ray results show large lobe solid changes, small lobe infiltration, and abscess formation. The treatment can choose β-lactam antibiotics, such as ampicillin, or directly give ceftazidime and other third-generation cephalosporins. In severe cases, aminoglycosides or quinolones antibiotics are given for active anti-infection treatment, such as common streptomycin, gentamicin sulfate, ciprofloxacin hydrochloride, etc., as well as the administration of drugs such as ambroxol hydrochloride for sputum chemotherapy; 3. Respiratory tract infections: including acute sinusitis, pharyngitis and tracheal or bronchitis, etc., when there is postnasal drip of secretions, or when the inflammation damages the bronchial mucosa, resulting in mucosal congestion and edema. There is an increase in the permeability of the walls of bronchial capillaries, and small brown jelly-like clots in the sputum accompanied by oxidized hemoglobin components in the sputum. It is usually necessary to give anti-infective treatment such as penicillin and ceftriaxone sodium for infectious diseases, and after the infection is controlled, the nature of sputum can be improved.