What are the symptoms of lung cancer and how can I detect . I have bn suffering from breathing problems. My nose gets congested often. Once doctor told me I hv bn suffering from sinus. Yesterday I felt a bit headache in the evening.It was not that extreme. I have been smoking fr around 9-10 years. Sometimes I get chest pain fr 2/3 days but that goes away by itself and not frequent. Do I need to be worried about cancer