Thanks for your question on Healthcare Magic. I can understand your concern. Yes, person can survive with only one lung but he can not live like normal individual. He gets shortness of breath, coughing, chest pain, palpitations, chest tightness etc even with mild exertion. So he can live normal life on bed but as soon as he does any activity he will have breathlessness and coughing. Your father wad a smoker and damaged his only lung too. So he should do Complete bed rest if he want to live longer. You can enroll him in pulmonary rehabilitation center where chest physiotherapy and deep breathing exercises are done. These will improve single lung functions. You should also vaccinate him with pneumococcal and influenza vaccines to prevent recurrent respiratory tract infections. Don t worry, he will live longer with all these. Hope I have solved your query. I will be happy to help you further. Wishing good health to your father. Thanks.