Do you think my dad has lung cancer?

My dad is 48 years old and has been smoking since he was 10. He smokes around 7 cigarettes a day ATLEAST. A few months ago he had a flu and had this nagging cough 2 weeks after that. I got a little concern but after a month he stopped coughing consistently. For the 4 months now I've noticed that he's coughing every 5 minutes but it's like a dry cough like. When he's sitting on the chair, he always wants to clear his throat but kind of holds back to cough but then he has too every 5 minutes. I'm worried, he's showed me he gets pains from his back and arm and I've recently watched a video and the same symptoms he is having. He randomly got a few headaches the other day and I was quite worried also... and his hoarse voice has been on for a few days now. I know you're going to say, LET HIM SEE A DOCTOR.. But do u think this is a good sign? I love my dad and I don't want anything happening to him.