Cancer is a disease in which cells in the body grow out of control. When cancer starts in the lungs, it is called lung cancer.
Lung cancer is one of the most common cancers in the United States. Skin cancer is the most common form of cancer diagnosed in the United States, followed by breast cancer (among women) and prostate cancer (among men). More people in the United States die from lung cancer than any other type of cancer.
This is true for both men and women. After increasing for decades, lung cancer rates are decreasing nationally, as fewer people smoke cigarettes and as lung cancer treatments improve. People with lung cancer are living longer after their diagnosis because more cases are found early, when treatment works best.
Cigarette smoking is the number one cause of lung cancer. Lung cancer also can be caused by using other types of tobacco (such as pipes or cigars), breathing secondhand smoke, being exposed to substances such as asbestos or radon at home or work, having certain gene mutations (unusual changes made when your body’s cells are dividing), or having a family history of lung cancer. Lung cancer can happen in people who never smoked or smoked fewer than 100 cigarettes in their lifetime.
Different people have different symptoms for lung cancer. Some people have symptoms related to the lungs.
Some people whose lung cancer has spread to other parts of the body (metastasized) have symptoms specific to that part of the body. Some people just have general symptoms of not feeling well. Most people with lung cancer don’t have symptoms until the cancer is advanced.
Most of the time, lung cancer has no symptoms in its early stages. Your lungs don’t have many nerve endings, so a tumor can start to grow there without causing pain. You may not notice the signs until your cancer has begun to spread.
These problems usually happen because of blocked breathing passages or because the cancer has spread farther into the lung, nearby areas, or other parts of the body.
This early stage of lung cancer often doesn’t cause any symptoms. Stage I lung cancer is more likely to be caught because you had a screening, not because you noticed anything wrong.