As can be expected, the symptoms and signs of lung cancer depend upon the site of involvement and the extent of involvement with the tumor. The most common symptoms of lung cancer are summarized below :
Cough is an important symptom of lung cancer, but it is difficult to distinguish cough associated with lung cancer from cough associated smoking or cough associated with chronic lung conditions like COPD that has resulted from smoking. If a patient who had chronic cough, shows changes in the pattern of cough, possibility of lung cancer should be considered.
Again, shortness of breath associated with lung cancer is difficult to differentiate from the one that is associated with COPD. As mentioned above a change in pattern of respiratory difficulty should cause concern for the development of lung cancer.
- Hemoptysis (spitting blood)
If Hemoptysis occurs in a patient with history of smoking, lung cancer should be suspected and appropriate work up is to be done to confirm or exclude this possibility.
Many times lung cancer makes its initial presentation in the form of a newly developed pneumonia. The growing tumor may cause obstruction of the airways, and cause what is called "Post obstructive pneumonia ". Patients who develop pneumonia may be advised to get repeat chest X-rays to make sure that all the pneumonia is resolved completely and no residual opacities are visible.
Lung cancer may spread to the inner lining, or outer covering of the lungs (known as plura) and this may result in development of fluid accumulation between the lung and the chest wall (plural effusion). Development of plural effusion may result in increased shortness of breath.
Lung cancer can infiltrate into the chest wall and may cause pain in the chest. Development of chest pain in a high-risk person should alert the physician to the possibility of lung cancer with chest wall invasion, or plural involvement.
Tumors in the apex (called pancoast's tumors, pancoast's tumor, pancoast tumor or pancoast tumors) of the lung may invade in to the surrounding nervous structures causing pain in the shoulders or arms. Tumors in these areas are difficult to be seen on a chest X-ray, hence patients who has symptoms suggestive of pancost 's tumors. Tumors infiltrating into the diaphragm may also produce shoulder pain.
Change in the voice pattern (hoarseness of voice) can be a symptom of lung cancer. This occurs more commonly with left sided tumors and happens because of the pressure effect on one of the nerves that comes from the chest to the vocal cord (called recurrent laryngeal nerve).
Lung cancer may cause other symptoms due to pressure effects. Pressure on the esophagus can lead to difficulty in swallowing (dysphagia). Pressure on the superior vena cava that returns blood from the upper part of the body to heart can lead to a condition called superior vena cava syndrome which is associated with redness and swelling of the upper part of the body. Wheezing and shortness of breath can be caused by direct obstruction of a large airway structure. Tumors close to the heart can infiltrate into the outer covering of the heart called pericardium and may cause accumulation of fluid between the heart and the outer covering of heart (called pericardial effusion).
The above information thankfully comes from the medicineworld.org at the following link.