Approximately 25% of individuals who develop lung cancer do not exhibit any symptoms prior to diagnosis. Rather, these people are generally diagnosed as a result of routine physical exams or testing. In some cases, the warning signs are not present until the disease has progressed dramatically. The symptoms of lung cancer often depend upon the location of the tumor and its progression.
Respiratory Symptoms
Respiratory problems are among some of the earliest symptoms of lung cancer to develop. Respiratory symptoms may include a shortness of breath, wheezing, persistent or chronic cough, pain in the chest or lungs, repeated respiratory infections, bronchitis and coughing up blood.
Symptoms Caused by Location
Depending upon the location of the cancer and where it has invaded within the body, other symptoms may develop. For example, if the cancer has invaded the esophageal area, the patient may experience difficulty swallowing. Similarly, if the cancer is located around the nerves, a paralysis of the vocal cords or shoulder pain that shoots down the arm may occur. If the tumor is located in an area where it is obstructing a major airway, a collapsing of the lung may result, leading to infection.
Symptoms Resulting from Metastasis
If the lung cancer has metastasized, or spread, to the skeletal system, the patient may experience severe pain in the regions where the bone has been invaded. If the cancer has metastasized to the brain, any number of neurological symptoms may develop. The patient may experience seizures, headaches, blurred vision or loss of sensation to various parts of the body.
Paraneoplastic Symptoms
Paraneoplastic symptoms refer to those conditions that result from a production of hormone-like substances within the tumor cells. Paraneoplastic syndromes typically occur more often with small-cell lung cancer, though they may develop with any type of tumor. In some instances, an over secretion of the cortisol hormone is produced by the adrenal glands as the result of an extra hormone secreted by the cancer cells. In other cases, a substance that is similar to parathyroid hormone is produced by the cancer cells, resulting in increased calcium levels within the bloodstream. Paraneoplastic symptoms may include a club-like appearance of the fingers as a result of extra tissue deposits under the nails, the formation of new bone in the arms and lower legs or anemia.
Non-specific Symptoms
In many cancers, a number of non-specific symptoms develop. These may include weight loss, fatigue, skin rashes and muscle weakness. In addition, a number of psychological symptoms may exist, such as sudden mood changes or depression.
Anyone who experiences any of the early symptoms of lung cancer should seek the assistance of a medical professional immediately in an effort to treat the disease as soon as possible.