1. Endless Cough.
When experiencing a cough for more than a week without a legitimate medical cause, such as a cold or a respiratory infection, it is possible that the cough is due to lung cancer. A prolonged cough can be one of the earliest signs of lung cancer, as this will occur when there is a tumor obstructing or irritating the airway. If you experience a cough for several weeks and there is no other sickness, you should get checked out by a medical professional.
