Lung cancer in its early stage and sometimes even later may not cause any signs and symptoms. In its advanced stage, the cancer cells interfere with normal lung function. The symptoms associated with lung cancer can result from the original tumor or from tumors that have spread to other organs. The cancers are usually identified incidentally when a chest x-ray is performed for another reason.

Common signs and symptoms of lung cancer are :

A cough that does not go away and gets worse over time
Coughing up blood (hemoptysis) or bloody mucus.
Chest, shoulder, or back pain that doesn't go away and often is made worse by deep
hoarseness
Weight loss and loss of appetite
Increase in volume of sputum
Wheezing
Shortness of breath
Repeated respiratory infections, such as bronchitis or pneumonia
repeated problems with pneumonia or bronchitis
fatigue and weakness
new onset of wheezing
swelling of the neck and face
Clubbing of the fingers and toes. The nails appear to bulge out more than normal.
Some patients may have paraneoplastic syndromes which are caused by biologically active substances that are secreted by the tumor.