There are a variety of lung cancer causes and risk factors. Some risk factors can be controlled, for instance, by quitting smoking. And other factors can't be controlled, such as your family history. Risk factors that may cause you to have an increased risk of developing lung cancer include:
- Smoking. Smoking remains the greatest risk factor for lung cancer. The risk of lung cancer increases with the number of cigarettes you smoke each day and the number of years you have smoked. Quitting at any age can significantly lower your risk of developing lung cancer.
- Exposure to secondhand smoke. Even if you don't smoke, your risk of lung cancer increases if you're exposed to secondhand smoke.
- Exposure to radon gas in the home or in mining work. Radon is produced by the natural breakdown of uranium in soil, rock and water that eventually becomes part of the air you breathe. Unsafe levels of radon can accumulate in any building, including homes. Radon testing kits, which can be purchased at home improvement stores, can determine whether levels are safe. If unsafe levels are discovered, remedies are available.
- Exposure to asbestos and other chemicals. Workplace exposure to asbestos and other substances known to cause cancer — such as arsenic, chromium and nickel — also can increase your risk of developing lung cancer, especially if you're a smoker.
- Family history of lung cancer. People with a parent, sibling or child with lung cancer have an increased risk of the disease.
- Certain smoking-related lung diseases. Smokers with certain lung diseases, such as emphysema, may have an increased risk of lung cancer.
- You are over 65 years of age.