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Can I Get Lung Cancer if I Don't Smoke?

Several Factors Contribute to Lung Cancer, with Smoking Being the Most Significant. Though Being a Non-Smoker Can Reduce Your Risk, You Can Still Develop the Disease.

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Dayton Respiratory Center

Jul 06 2022

7 mins read

The link between smoking and lung cancer is pretty clear. But what if you’ve never smoked a day in your life? Can you still get lung cancer?

It's a common misconception that only smokers can get lung cancer.

Lung cancer is one of the leading causes of cancer death worldwide, and smoking is the primary risk factor. But nonsmokers can also get lung cancer.

In the United States, an estimated 10%-20% of lung cancers each year occur in people who have never smoked or smoked not more than 100 cigarettes in their lifetime.

So, how does someone who hasn't smoked get lung cancer? This article will help you understand the reason.

What Is Lung Cancer?

Cancer is a disease characterized by an out-of-control growth of abnormal cells capable of destroying normal cells or tissues. Cancer that develops in the lungs is known as lung cancer.

When normal cells grow old or get damaged, they die and are replaced with new cells. Cancer cells, however, keep dividing and making new, abnormal cells.

People who develop lung cancer are characterized as smokers, non-smokers and never-smokers. Nonsmokers are people who don't currently smoke but have smoked nearly 100 cigarettes in their lifetime. Never-smokers are people who haven't smoked or smoked less than 100 cigarettes.

There are two main types of lung cancer: Non-small cell lung cancer (NSCLC) and Small cell lung cancer(SCLC). Non-small cell lung cancer is the most common type, accounting for about 80%-85% of all cases. Small cell lung cancer though less common, is mainly seen in smokers.

Can I Get Lung Cancer if I Don't Smoke?

It’s a common misconception that only smokers can get lung cancer.

While smoking is the leading cause of the disease, lung cancer can also occur in people who have never smoked. However, smokers are 15 to 30 times more likely to get lung cancer than non/never smokers.

The American Cancer Society (ACS) estimates that nearly 20% of lung cancer deaths occur in people who have never smoked.

What Are the Causes of Lung Cancer in Non-Smokers?

In non/never smokers, lung cancer might not be due to a single factor but a combination of factors. More research is being done in this area to find out the exact reason for lung cancer in non/never smokers.

Lung cancer in nonsmokers is mainly attributed to mutations in the DNA. Mutations are changes in your DNA that cause certain cells to work differently. Various factors can cause mutations and increase your risk of lung cancer.

Let's discuss a few factors that increase the risk of lung cancer.

Secondhand smoke

Exposure to secondhand smoke, even if you’ve never smoked yourself, is a leading cause of lung cancer. It is also known as passive smoking.

Inhaling other people’s cigarette smoke, whether from a friend, family member or stranger, can damage your lungs and increase your risk of developing cancer.

Many people do not realize that exposure to secondhand smoke can be just as harmful as smoking cigarettes yourself. It was found that secondhand smoke was responsible for about 7,333 lung cancer deaths in the United States in 2006.

Radon Gas

Another leading cause of lung cancer in non-smokers is radon exposure.

Radon is a colorless and odorless gas that comes from the natural breakdown of uranium in soil, water, and rock. It can enter your home, school or workplace through cracks in the foundation or other openings. Exposure to high levels of radon over time can lead to lung cancer.

According to the United States EPA (Environmental Protection Agency), nearly 21,000 lung cancer deaths occur due to radon exposure.

Air Pollution

Air pollution increases the risk of lung cancer, especially in urban areas. Air pollution is mainly caused by vehicle exhaust and industrial emissions.

Lung cancer rates are higher in cities due to heavy traffic. In the U.S., air pollution contributes to 1%-2% of lung cancer cases.


Asbestos exposure is another cause of lung cancer. Asbestos is a heat-resistant mineral that has been used in insulation and other products for many years.

When asbestos fibers are inhaled, they can lodge in the lungs and cause lung cancer. People who work with asbestos are at higher risk of lung cancer.

Carcinogens at Workplace

Carcinogens are cancer-causing agents that can increase your risk of lung cancer. People exposed to chemicals like arsenic, beryllium, cadmium, silica, vinyl chloride, etc., at their workplace are more prone to the disease.

Family History

People with a family history of lung cancer are at more risk because they may inherit certain genetic mutations that make them more susceptible to lung cancer. Family history is not a major contributing factor to lung cancer, but it cannot be ignored; it can make you 2-3 fold more susceptible to the disease.

Reasons for Lung Cancer in Nonsmokers


What Are the Symptoms of Lung Cancer in Non-Smokers?

The symptoms of lung cancer in non-smokers are often the same as those in smokers. They include:

  • Shortness of breath,
  • Persistent cough
  • Pain in the chest or back
  • Hoarseness
  • Weight loss
  • Fatigue
  • Loss of appetite
  • Difficulty in swallowing
  • Frequent infections, including pneumonia

Type of Lung Cancer Seen in Non-Smokers

Adenocarcinoma, a non-small cell lung cancer(NSCLC), is the most common type (50%-60%) of lung cancer in non-smokers. These cancers begin in the cells that line the air sacs in your lungs and secrete mucus.

Squamous cell carcinomas, another type of non-small cell lung cancer(NSCLC), characterized by the abnormal growth of thin, flat cells that line the inside of your airways, account for 10% to 20% of lung cancers in nonsmokers.

Though very rare in non-smokers, small cell lung cancer (SCLC) causes 6%-8% of lung cancers.

NSCLC tend to grow more slowly and be less aggressive than SCLC.

How Can a Non-Smoker Prevent Lung Cancer?

The best way to prevent lung cancer is to avoid exposure to second-hand smoke. According to the Centers for Disease Control and Prevention, “There is no risk-free level of exposure to secondhand smoke.”

If you are a non-smoker, avoid places where people are smoking or try to limit your time in smoky areas.

You can further reduce your risk of lung cancer by avoiding excessive exposure to radiation and environmental pollutants. If you work with hazardous materials, make sure to take the necessary safety precautions.

If there is a history of lung cancer in your family, talk to your doctor. While you can't change your family history, you can take steps to reduce your risk of lung cancer by not smoking and avoiding exposure to secondhand smoke and other airborne pollutants.

Eating a healthy diet can also reduce your risk of developing lung cancer. A diet high in fruits and vegetables and low in saturated and trans fats can help reduce your risk.

What Are the Treatment Options Available?

If you have been diagnosed with lung cancer, your doctor will work with you to develop a treatment plan that is right for you. Your doctor will consider a variety of factors, including the type and stage of your lung cancer, your overall health, and your personal preferences.

Some common treatment options for lung cancer include surgery, radiation therapy, targeted therapy and chemotherapy, and these are all effective in different ways and have different side effects. It is important to discuss all of your options with your doctor to decide which is the best for you.

Clinical trials may also be an option for you. These trials test new treatments that are not yet available to the general public. They can be an effective way to receive cutting-edge treatment, but they may also have more risks than other options. Your doctor can help you decide if a clinical trial is right for you.


While smoking is the primary cause of lung cancer, it’s not the only one. If you don’t smoke, you can still reduce your risk by avoiding exposure to secondhand smoke and environmental pollutants and by maintaining a healthy lifestyle. Many effective treatments are available, and you can improve your chances of beating the disease with early diagnosis. If you are concerned about developing lung cancer, talk to your doctor about ways to conduct an early diagnosis or how to reduce your risk.

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