Shortness of breath. This symptom remains limited longer than others. While shortness of breath is one of the first signs of lung cancer. Generally, patients and doctors are looking for causes of dyspnea in other diseases, most often heart disease, but they forget about the possibility of the risk of propagation cancer. In some cases, persons believe that shortness of breath is an effect from weak physical activity or aging. Do not neglect such symptom, especially when these signs continue for a long time.