Brief Answer: Go for pulmonary function testing, chest xray Detailed Answer: Hi, Thanks for your query. Two things are worth mentioning here. Smoker even at this frequency may cause, Airway loss of ciliary mechanism to handle the mucous and bacteria. This can be one of the cause for this cough....better say smoker's cough. Drinking if leads to altered consciousness may lead to depressed gag reflex, so there may be aspiration of microbe rich oral secretion into the trachea. This can cause repeated infection and may lead to lung abscess. He also may be having obstructive sleep apnoea as you have told about the noisy sleep. What I feel is, he must go for sputum examination, chest x-ray and pulmonary functioning testing to reach to correct diagnosis. If needed CT scan thorax can be done.... Best wishes

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