Lung cancer is a type of cancer that begins in the lungs. Your
lungs are two spongy organs in your chest that take in oxygen
when you inhale and release carbon dioxide when you exhale. Lung
cancer is the leading cause of cancer deaths in the United
States, among both men and women. Lung cancer claims more lives
each year than do colon, prostate, ovarian and breast cancers
combined. People who smoke have the greatest risk of lung
cancer. The risk of lung cancer increases with the length of
time and number of cigarettes you've smoked. If you quit
smoking, even after smoking for many years, you can
significantly reduce your chances of developing lung cancer.
Lung cancer typically doesn't cause signs and symptoms in its
earliest stages. Signs and symptoms of lung cancer typically
occur only when the disease is advanced. Signs and symptoms of
lung cancer may include: When to see a doctor Make an
appointment with your doctor if you have any signs or symptoms
that worry you. If you smoke and have been unable to quit