What are the symptoms of lung cancer?

Symptoms of lung cancer are varied depending upon where and how widespread the tumor is. Warning signs of lung cancer are not always present or easy to identify. A person with lung cancer may have the following kinds of symptoms:

• No symptoms: In up to 25% of people who get lung cancer, the cancer is first discovered on a routine chest X-ray or  CT scan as a solitary small mass sometimes called a coin lesion, since on a two-dimensional X-ray or CT scan, the round tumor looks like a coin. These patients with small, single masses often report no symptoms at the time the cancer is discovered.

• Symptoms related to the cancer: The growth of the cancer and invasion of lung tissues and surrounding tissue may interfere with breathing, leading to symptoms such as cough, shortness of breath,  wheezing,  chest pain, and coughing up blood  (hemoptysis). If the cancer has invaded nerves, for example, it may cause  shoulder pain that travels down the outside of the arm (called Pancoast's syndrome) or  paralysis  of the vocal cords leading to  hoarseness . Invasion of the esophagus may lead to difficulty swallowing  (dysphagia). If a large airway is obstructed, collapse of a portion of the lung may occur and cause infections (abscesses, pneumonia) in the obstructed area.