Coughing even after 5 months of quitting smoking may be due to smoking cessation syndrome or the presence of other diseases that can cause coughing. 1. Smoking cessation syndrome: Cigarettes are harmful to health, and long-term smoking can cause irritation and damage to the lungs, which can produce a lot of mucus. When you quit smoking, the mucus becomes loosened, stimulating the cough reflex to expel phlegm, and you may experience the symptom of coughing after 5 months of quitting smoking, which is a normal symptom and does not require medication. 2. Other diseases: Many diseases can cause chronic cough, including infectious diseases (such as pneumonia, bronchitis, tuberculosis, etc.) and non-infectious diseases (such as chronic obstructive pulmonary disease, lung cancer, pulmonary fibrosis, gastroesophageal reflux stimulation, cough variant asthma, etc.). Chronic cough may occur in the presence of these diseases, but is not associated with smoking cessation. If the cough symptoms fail to improve or even gradually worsen, you need to consult a regular hospital in time and cooperate with the doctor to improve the examination and standardize the treatment.