Hi welcome to health care magic..... You have smoking habit , so your lung might be affected .... Here idiopathic pulmonary fibrosis has to be ruled out .... Smoking also lead chronic obstructive pulmonary disease .... For which pulmonary function test by spirometry done.... It will able to diagnose your case as well assess severity.... You might given bronchodilator or steroid depending on cause ... Also investigate with bp checking , stress test and ECG as smoking can lead coronary artery disease. Hope your concern solved. Take care.