Conversation: The conversation between human and AI assistant.
[|Human|] My dad sixty seven years old smoker he had a bad cough for two months cough up with yellow mucus and it tastes really bad and he always feel very tired and weak and lost weight he did a lot of testing cta scan and it didn t show any sign of cancer he coughs a lot and especially at night
[|AI|]  Thanks for your question on Chat Doctor. I can understand your fathers situation and problem. Possibility of COPD (chronic obstructive Pulmonary disease) is more in his case. His CT scan is not suggestive of any infection, so no need to worry about tuberculosis or other lung infection. He was a smoker, having cough with expectoration and tiredness. All these are favoring COPD more. So better to consult pulmonologist and get done 1. Clinical examination of respiratory system 2. PUT (Pulmonary Function Test). PFT is must for the diagnosis of COPD. It will also tell you about severity of the disease. And treatment of COPD is based on severity only. He will improve with inhaled bronchodilators and inhaled corticosteroid (ICS). Bucolic, expectorant and antioxidants Chat Doctor.  So consult pulmonologist and discuss all these. Hope I have solved your query. Wishing good health to your father. Thanks.