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There are two main types of cancer that start in the lungs: small cell and non-small cell lung cancer.
Lung cancers are thought to start as areas of precancerous changes in the cells lining the bronchi and parts of the lung, such as the bronchioles or alveoli. Lung cancer is among the hardest cancer type to treat for several reasons.
Some lung cancer patients -- about 15 percent -- have no symptoms at all when their cancer is diagnosed. These cancers are usually identified accidentally during chest X-rays for another condition.
In many cases, by the time the lung cancer is diagnosed it has spread to other parts of the body, making it more difficult to treat than other cancer types. For this reason, the five-year survival rate for lung cancers is only 15 percent according to the Cleveland Clinic.
Most people (85 percent) do have some signs when lung cancer is present, including cough, coughing up blood, chest pain and shortness of breath. If you experience any of these symptoms, it is important to seek immediate medical care.
A new cough in a smoker or former smoker should raise concern. A health care provider should evaluate a cough that persists without getting better or worsens over time.
Coughing up blood, known as hemoptysis, occurs in a significant number of people with lung cancer. Any amount of coughed up blood is reason for concern, and should be addressed immediately.
Chest pain is a symptom about one in four people with lung cancer experience. The pain is often described as dull, aching, and persistent.
Shortness of breath is a common lung cancer symptom. It usually results from an airflow blockage in part of the lung, fluid collecting around the lung (pleural effusion), or the tumor spreading throughout the lungs.
Wheezing or hoarseness may signal blockage or inflammation in the lungs associated with cancer.
People with lung cancer often experience repeated bouts of bronchitis, pneumonia or other respiratory illnesses. Swollen lymph nodes near the lungs have also been linked to lung cancer.