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What Is the Main Reason for Lung Cancer?

“Lung cancer is one of those cancers where the cause is known, and the cause is something that we do willingly to get cancer.” – Dr. Arvind Kumar.

It is common knowledge that anyone can get or develop lung cancer. You must be thinking, “But I don’t smoke. So how did I get lung cancer?” Although smoking is the most common cause of lung cancer, it isn’t the only one.

Several factors can trigger the mutation that leads to the signs of lung cancer. Some involve the most common trigger of smoking; some might develop lung cancer after inhaling toxic fumes from the factories or the nearby areas.

This article will explore all the potential causes and risk factors for lung cancer that you need to be aware of.

Top Causes of Lung Cancer

Lung cancer is the second-most common type of cancer affecting people globally. It is more common in men than women, especially due to the causes.

However, you need to realize that the reason for lung cancer isn’t just limited to smoking. Even non-smokers have a risk of developing lung cancer due to multiple reasons Causes of Lung Cancer.

The following are some of the reasons and triggers worth considering.

1. Smoking

Smoking is the leading cause of lung cancer. Around 80-85% of the diagnosed lung cancer patients are chronic and heavy smokers. This means a direct cause-and-effect relationship exists between smoking and lung cancer.

The trigger behind smoking as a potential risk of lung cancer is that its not just active smoking that one must be aware of. Even second-hand smoke can potentially contribute to the risks of lung cancer in patients.

While active smoking is already putting you at risk of lung cancer, living or being surrounded by an active smoker also enhances your risk of lung cancer by 30%.

2. Air Pollution

Another one of the numerous reasons for lung infection and cancer is the polluted air we breathe. The harsh and unhealthy fumes from factory exhaust, coal-fired plants, cars, etc., consistently pollute our air, enhancing the risks of lung cancer in patients.

Rapid industrialization is elevating the degree of particle pollution in the air, leading to heightened risks of lung cancer in most patients (including non-smokers).

3. Genetic Issues

When analyzing genetic factors causing lung cancers, there are two situations to remember.

  • You have inherited gene changes or genetic predisposition
  • You have the external trigger factors altering the DNA of the lung cells

Either case of genetic complications can lead to an aggressive form of lung cancer that might require more potent treatment options like chemotherapy, radiation, immunotherapy, etc.

The external trigger factors have the potential to lead to DNA changes in the lung cells, which, in turn, trigger the oncogenes, leading to abnormal cell growth in the lungs.

On the flip side, some lung cancer patients inherit genetic anomalies that lead to the development of lung cancer down the line. Certain genes might enhance the risks of developing lung cancer, but they aren’t always the sole reason. The condition is exacerbated by poor lifestyle choices like smoking, tobacco use, unhealthy diet, secondhand smoking, etc.

4. Exposure to Chemicals

Chemicals, both the industrial and the ones we use around the house, have imminent impacts on the development of lung cancer in patients.

People living in rural areas in India (and the world) who use biomass fuel, wood, etc., for burning emit toxic fumes, which contribute to elevated risks of lung cancer in the patients.

These account for the reasons for lung cancer in non-smokers, which has witnessed a sharp rise in the last decade.

Besides these, individuals who work in factories or industries that process harmful chemicals like uranium, asbestos, arsenic, cadmium, nickel, petroleum products, etc., also notice an alarming rise in the risks of developing lung cancers.

5. Radon Exposure

Besides these hazardous chemicals, radon exposure accounts for one of the major reasons for lung cancer right after smoking.

Radon is naturally found in the soil, and the rapid commercialization in the world is a leading reason for lung cancer behind radon exposure in households.

Further paired with the ill habit of smoking and the deteriorating quality of air around us, lung cancer is a disease we sit and feed into.

6. History of Radiation Therapy

Patients who have undergone some form of radiation therapy earlier in life for lung cancer treatment in India have elevated risks of developing lung cancer later in life.

Typically, high-energy radiation beams are easy triggers for developing secondary cancers in patients.

Pair that with an already existing smoking habit or poor lifestyle choices, and the risk of developing lung cancer is tenfold.

7. Family history of Lung Cancer

If your parents, siblings, or even a child have been diagnosed with lung cancer, it automatically increases your risk of developing it.

The complications related to acquired gene changes in the body are also responsible for developing lung cancer in patients. The acquired mutations typically happen due to household and environmental pollution complications.

One of the most common causes of acquired gene lung cancers is the RB1 tumor suppressor gene, which leads to small-cell lung cancer. On the flip side, the p16 tumor suppressor gene and the K-RAS oncogene are quintessential to developing non-small cell lung cancer.

For a more elaborate understanding of the causes of lung cancer.


Lung cancer accounts for the most cancer-related deaths in the world. If you are a smoker or exposed to chemicals and harmful gases that elevate your risks of lung cancer, put precautionary measures into place.

If you are at risk of lung cancer due to familial medical history, regular screening is ideal for an early diagnosis and cure. At Medanta, our team of leading lung cancer specialists, led by Dr. Arvind Kumar, have treated and cured hundreds of lung cancer patients, putting the patients in remission.

Identifying the signs and getting an early diagnosis is key to a warranted cure for this deadly disease.

For more details and consultations, visit


1. What are the complications of lung cancer?

Some of the most common complications related to lung cancer are shortness of breath, pain in the chest, coughing up blood, fluid accumulation in the chest, metastasis of cancer, etc.

2. What is the biggest cause of lung cancer?

Smoking is the number one cause of lung cancer, accounting for 80-85% of cases diagnosed globally.

3. Who is at risk of getting lung cancer?

Anyone can develop lung cancer, but smokers, people with a family history of lung cancer, factory workers, etc., are at heightened risks of getting lung cancer.

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