Im a 30yr old male smoker. I smoke a little more than a pack a day. Im having pains in my chest on the left side in the same spot in the front as the back. Feels like im being stabbed in one spot over and over. Sometimes it feels like it is in my chest, sometimes it feels like its in my back. The pain ranges from a 2 to a 6. 10 being the worst. It happens on and off all day. Is it serious. Should i see a doctor soon?