A DNA mutation causes lung cancer. Cells divide and replicate to form identical cells. In this way, your body is constantly renewing itself. Inhaling harmful chemicals like cigarette smoke, asbestos, and radon damages the cells that line your lungs. At first, your body may be able to repair itself. With repeated exposure, the damage to your cells increases. Over time, cells begin to grow uncontrollably. This is how cancer can develop.

Several changes have to occur for cancer to develop. The buildup of extra cells causes tumors. The can be either benign, or noncancerous, or malignant, which means cancerous. Malignant lung tumors can be life-threatening. They can spread and even return after the doctor has removed them.


Current research suggests that if a member of your immediate family, such as your parent or sibling, has or had lung cancer, you may have a slightly higher risk of developing the disease. This is also the case if you have multiple family members who’ve had lung cancer.

This is true even if you don’t smoke. At this point, it’s unclear whether genetics cause lung cancer or merely increase your chances of developing it.


According to the Lung Cancer Alliance (LCA), the average age in the United States for a lung cancer diagnosis is around 70. Only about 10 percent of lung cancers occur in people younger than 50. The older you are, the longer you’ve been exposed to harmful chemicals. This increases your risk of cancer.

Past lung disease

If you have a history of chronic illnesses that affect the lungs, you may be at a greater risk of developing lung cancer. Lung diseases can cause inflammation and scarring in the lungs. These include tuberculosis and chronic obstructive pulmonary disease, which includes chronic bronchitis and emphysema.

Radiation therapy to the chest

Radiation therapy for treating other cancers may increase your risk of lung cancer. This risk is higher if you smoke.

Secondhand smoke

You’re at risk for lung cancer if you don’t smoke but you’re exposed to cigarette smoke regularly in your daily environment, such as:

  • at home
  • at work
  • in restaurants
  • in bars

According to the LCA, secondhand smoke increases your risk of lung cancer by 20 to 30 percent.


Although nonsmokers can get lung cancer, smoking tobacco, such as by using cigarettes, cigars, and pipes, is the top risk factor for lung cancer. According to the Centers for Disease Control and Prevention (CDC), about 90 percent of all lung cancer deaths in the United States are due to smoking. Tobacco and tobacco smoke contain 7,000 chemicals, many of which are carcinogenic. Inhaling the chemicals in a cigarette immediately triggers a change in lung tissue. Initially, your body is able to repair the damage. Its ability to do so decreases as exposure continues. The more frequently you smoke and the longer you smoke, the greater your chances of developing lung cancer.


You may have an increased risk for lung cancer if you don’t eat a diverse mix of healthy foods like fruits and vegetables. This is especially true if you’re a smoker.

According to the Mayo Clinic, exposure to certain toxins in the environment can increase your risk of developing lung cancer. These toxins include radon, asbestos, and other chemicals.


Radon is an odorless, colorless, and tasteless gas that occurs naturally with the breakdown of uranium in rocks and soil. These gases can seep into building foundations and into living and working spaces. Because radon is difficult to detect, you could have exposure to it without knowing it. People who smoke have an increased risk from the effects of radon than those who don’t smoke. According to the LCA, radon is the second leading cause of lung cancer in the United States.


Asbestos is an industrial material that people use in construction for insulation and as a fire retardant. When the material is disturbed, small fibers become airborne and can be inhaled. You’re at an increased risk of developing lung cancer if you’re exposed to asbestos on a regular basis.

Other chemicals

Other chemical exposures can raise your lung cancer risks. Some examples of these chemicals are:

  • arsenic
  • beryllium
  • cadmium
  • vinyl chloride
  • nickel compounds
  • chromium compounds
  • coal products
  • mustard gas
  • chloromethyl ethers
  • diesel exhaust

Most cases of lung cancer are preventable. You can significantly limit your chances of developing lung cancer by avoiding exposure to risk factors. Smoking is the top risk factor for lung cancer.

Quitting smoking

Quitting is the most important thing you can do to reduce your risk of lung cancer. Your lungs will begin to heal themselves almost immediately. The amount of time you smoked and the frequency will affect the ability of the lungs to repair. But even after many years of smoking, quitting can significantly reduce your risk of lung cancer.

Avoiding asbestos and radon

If you work around asbestos or other harmful materials, be careful to limit your exposure as much as possible. Radon testing is available for home and commercial spaces. If you live or work in an old building and suspect the presence of either radon or asbestos, testing for unsafe levels can provide you with peace of mind.

Maintaining a healthy diet

Nutrition is important for maintaining good health. A diet high in the following provides your body with the nutrition it needs to function properly and heal damaged cells:

  • fruits
  • vegetables
  • vitamins
  • minerals

You can also do the following to maintain a healthy diet:

  • Eat five or more servings of fruits and vegetables per day.
  • Include other plant-based foods like beans and grains.
  • Stay away from high-fat foods.
  • Avoid drinking alcohol or limit the amount you drink.