What causes lung cancer?

One of the most common causes of lung cancer is tobacco. People who smoke or are around secondhand smoke for a long time are more likely to develop lung cancer.

It is important to remember that even non-smokers and those who have never been around secondhand smoke can get lung cancer too. Scientists don’t know exactly what causes these people to get lung cancer, but they think some of the things below might increase a person’s risk of developing it.