One fourth of all people with lung cancer have no symptoms when the cancer is diagnosed. These cancers are usually identified incidentally when a chest x-ray is performed for another reason. The other three fourths of people develop some symptoms. The symptoms are due to direct effects of the primary tumor; to effects of metastatic tumors in other parts of the body; or to malignant disturbances of hormones, blood, or other systems.

Symptoms of primary lung cancers include cough, coughing up blood, chest pain, and shortness of breath.

• A new cough in a smoker or a former smoker should raise concern for lung cancer.
  
  
  
  
• A cough that does not go away or gets worse over time should be evaluated by a health care provider.
  
  
  
  
• Coughing up blood (hemoptysis) occurs in a significant number of people who have lung cancer. Any amount of coughed-up blood should cause alarm.
  
  
  
  
• Chest pain is a symptom in about one fourth of people with lung cancer. The pain is dull, aching, and persistent and may involve other structures surrounding the lung.
  
  
  
  
• Shortness of breath usually results from a blockage in part of the lung, collection of fluid around the lung (pleural effusion), or the spread of tumor through the lungs.
  
  
  
  
• Wheezing or hoarseness may signal blockage or inflammation in the lungs that may go along with cancer.
  
  
  
  
• Repeated respiratory infections, such as bronchitis or pneumonia, can be a sign of lung cancer.