Some cancers of the lung are caught early, before any warning signs show up, when a common x-ray of the chest is taken, generally for another reason. If a spot appears that could be a cancer, extra diagnostic tests can be performed to confirm that a cancer is present.

However, if you have not had a CT scan or a chest x-ray for a while, what is a symptom of lung cancer you ought to be looking for?

The very first and earliest symptom of lung cancer 肺癌 you could observe is a cough that doesn't go away. After further progress of your cancerous tumor, damage to cells of the lung takes place and your cough starts to supply blood.

As your cancer expands, it starts to reduce the quantity of air your lungs can handle. This produces a symptom of lung cancer you'll call difficulty in breathing. You often cannot take in adequate oxygen to supply your requirements.