A risk factor is anything that increases your chance of getting a disease. When it comes to cancer, risk factors can be what you eat, where you work, and who your parents are.

Naturally, it's understandable to worry a little if you have a risk factor for cancer. But keep a few things in mind:

• Risk factors can increase a person's chance of getting cancer. But: They are not always the cause of someone's cancer. Often, the exact cause is unknown.
• A person with few or no risk factors can develop cancer. But: A person with many risk factors may never develop cancer.
• Some risk factors, like family history, are beyond your control. But: Other risk factors, like smoking, are within your power to change.

It's no secret: Smoking tobacco is by far the leading risk factor for lung cancer. The longer you smoke, and the more you smoke each day, the higher your risk. Cigarettes are the main culprit, but cigar and pipe smoking are almost as likely to cause the disease. Smoking is linked to about 8 in 10 lung cancer deaths.

For people who smoke, this information might seem overwhelming. Yet, it's important to know you're in control of this risk factor. Quitting smoking, even after many years, can substantially lower your risk for lung cancer.

While people who smoke tend to be at the greatest risk, those who have never smoked at all can still get lung cancer. Other risk factors include:

Breathing in other people's smoke increases your own risk for lung cancer. But the truth is, it can be hard to avoid—especially for children of people who smoke. Keeping your home (and car) smoke-free is a great first step to protecting your loved ones.

Radon is a colorless, odorless, radioactive gas. It comes from uranium breaking down in rocks and soil. Outside, levels of radon are rarely a concern. It becomes dangerous when levels become concentrated in the lower parts of buildings, such as basements. People who have lived for a long time in homes with high levels of radon are at a greater risk for lung cancer.

The good news: If your home is tested and has high levels of radon, you can effectively fix the problem by installation of radon gas mitigation systems. The Environmental Protection Agency has resources in your area at www.epa.gov/radon.

Asbestos is a mineral fiber found in rocks and soil. Breathing it in can increase your risk for lung cancer. Asbestos is still present in many homes and older buildings but usually not considered harmful as long as it's not released into the air by deterioration, renovation, or demolition.

For years, manufacturers have used asbestos in insulation and other products. People who work with these products face a risk for exposure. Fortunately, standards have been set to lower these risks. The Occupational Safety and Health Administration has more information at www.osha.gov/asbestos.

Exposure to some chemicals can cause lung cancer. This includes inhaling arsenic, silica, coal products, and other chemicals that are mostly found in the workplace. If you work with chemicals, be sure to follow relevant health and safety guidelines.

Air pollution, particularly in high-traffic areas, appears to slightly increase one's risk for lung cancer.

Radiation therapy to the chest can be a necessary treatment for diseases like breast cancer and Hodgkin's lymphoma. Unfortunately, people who have received it are also at a higher risk for lung cancer.

People who have had lung cancer before are at risk of getting lung cancer again. And people with family members who have had lung cancer are at a greater risk themselves. Sometimes, shared household risk factors, such as secondhand smoke, are to blame. Other times, it's a matter of genetics. Some genetic changes that run in families are linked to lung cancer.

Talking with your healthcare provider about your risk factors can bring you greater peace of mind. You may find you can take steps to lower your risk, such as testing your home for radon or avoiding exposure to specific workplace chemicals.

If you've smoked for a long time and want to quit, you can always ask your healthcare provider for help. The CDC offers resources. Find out more at cdc.gov/quit or smokefree.gov

You can't get a routine screening for lung cancer, but if you're between the ages of 50 and 80, you may qualify for one. These screenings can sometimes detect the cancer early when it tends to be easier to treat.