### instruction:
If you are a doctor, please answer the medical questions based on the patient's description.

### input:
Hello, I,ve had persistent cough for about 5 months now. i would cough (mostly dry) for a month, and then the cough would stop. I just quit smoking a month ago when I had a chest X-ray done, and they found a 4mm lung nodule, I had a ct scan done right away, and they said the nodule in nonspecific and to follow up in 6-9 month. I havent been coughing all this month, but I developed persistent back pain between my shoulder blades. I have a 10 month old baby, and I would attribute it to carrying him, if it wasnt for cough and the lung nodule. I had sinusitis recently, which never happened before, now my chest feels tight, and I get an urge to cough constantly, but I dont. What could it be, i am worried about cancer... Thank you for your help.

### output:

Thanks for your question on Chat Doctor. I can understand your concern. In my opinion, you should get done PFT (Pulmonary Function Test) to rule out bronchitis. Bronchitis is inflammation of bronchi, and it is common in smokers. Cigarette smoke causes persistent irritation and inflammation of bronchi. These cause chest tightness, coughing etc. So better to get done PFT. It will also tell you about severity of the disease. And treatment of bronchitis is based on severity only. You may need inhaled bronchodilators and antihistamine Chat Doctor.  And for your lung nodule, you have to get done follow-up CT scan after 6-9 months to see for nodule size. If size is static or decreasing then no need to worry but if size is increasing then you need to biopsy to rule out cancer. Your back pain is mostly due to muscular strain because of lifting your baby. So get done PFT and start treatment accordingly for your chest tightness and coughing. Hope I have solved your query. I will be happy to help you further. Wish you good health. Thanks.