Lung cancer is one of the most common and serious types of cancer affecting both men and women around the world. According to the U.S. National Cancer Institute, about one in every 14 men and women in the United States will be diagnosed with lung cancer at some point during their lifetime. In recent decades, lung cancer has overtaken breast cancer as the leading cause of cancer-related deaths among women in the U.S. Despite these alarming statistics, understanding the major risk factors and recognizing early warning signs can significantly improve early detection and potentially save lives.

Risk Factors

Smoking
There is a very strong connection between lung cancer and cigarette smoking. Approximately 90% of lung cancer cases are linked to tobacco use. The risk increases with both the number of cigarettes smoked per day and the total number of years a person has smoked. Studies suggest that among people who smoke two or more packs of cigarettes daily, as many as one in seven may eventually die from lung cancer. Smoking cigars or pipes also increases the risk, though usually to a lesser extent than cigarettes.

Passive smoking (secondhand smoke)
Even if you do not smoke, exposure to secondhand smoke can still put your health at risk. Tobacco smoke contains numerous toxic and cancer-causing chemicals. The longer and more frequently you are exposed to smoke from other people, the higher your risk of developing lung cancer becomes, especially in enclosed spaces such as homes or workplaces.

Air pollution
Long-term exposure to heavily polluted air, including industrial emissions and vehicle exhaust, is believed to raise the risk of lung cancer. Research suggests that the risk associated with severe air pollution may be comparable to that of passive smoking, particularly in large urban areas.

Asbestos fibers and other hazardous chemicals
Although asbestos is now restricted or banned in many countries, it was widely used in the past, especially in construction and manufacturing. Exposure to asbestos fibers, as well as certain industrial chemicals such as arsenic, beryllium, cadmium, coal dust, silica, and nickel, can significantly increase the risk of lung cancer. People working in mining, construction, or chemical industries may face higher occupational exposure.

Radon gas
Radon is a naturally occurring radioactive gas produced by the breakdown of uranium in soil and rocks. It is colorless, odorless, and invisible, making it difficult to detect without testing. Radon can seep into homes through cracks in foundations and accumulate indoors, increasing the risk of lung cancer over time.

Heredity and genetics
Genetic factors may influence an individual’s susceptibility to lung cancer. People with a close family member who has had lung cancer are at a higher risk, even if they have never smoked.

Pre-existing lung diseases
Certain chronic lung conditions, such as chronic obstructive pulmonary disease (COPD) and pulmonary fibrosis (lung scarring), are associated with an increased risk of developing lung cancer.

Age
Age is another important risk factor. Nearly 70% of people diagnosed with lung cancer are over the age of 65, while fewer than 3% of cases occur in individuals under 45 years old.

Signs and Symptoms of Lung Cancer

Early-stage lung cancer often does not cause noticeable symptoms, which makes early detection challenging. Many warning signs appear only after the disease has progressed. However, people who have one or more risk factors should be especially alert and consider early screening when appropriate.

Common symptoms may include:

1. Persistent cough or changes in an existing cough
A cough caused by a cold usually resolves within one to two weeks. If a cough persists for a long time, worsens, or changes in character, medical attention is recommended. Smokers or people with chronic coughs should watch for changes such as coughing more frequently, a deeper or hoarser sound, coughing up blood, or producing more mucus than usual.

2. Shortness of breath
Feeling short of breath during activities that were previously easy may be a warning sign. This can occur if a tumor blocks or narrows an airway or if fluid accumulates in the chest due to cancer.

3. Chest, shoulder, or bone pain
Persistent pain in the chest, back, or shoulders may be related to lung cancer. If the cancer spreads to the bones, it can cause localized bone pain. When it spreads to the brain, symptoms such as headaches or neurological changes may occur. Ongoing or unexplained pain should always be evaluated by a doctor.

4. Wheezing
A whistling sound while breathing is often linked to asthma or allergies, but persistent wheezing can also be associated with lung cancer and should not be ignored.

5. Voice changes
Hoarseness or noticeable changes in voice tone or depth may occur. While temporary hoarseness is common with colds, persistent voice changes warrant medical evaluation.

6. Recurrent chest infections
Frequent or lingering infections such as bronchitis or pneumonia that do not fully resolve or keep returning may be a sign of an underlying problem.

7. Unexplained weight loss, loss of appetite, fatigue, and weakness
These symptoms are not specific to lung cancer and can occur with many conditions. However, if they are unexplained and persistent, further medical investigation is necessary.

How to Reduce the Risk of Developing Lung Cancer

Quit smoking
Stopping smoking is the most effective way to reduce the risk of lung cancer, regardless of age or how long you have smoked. Avoiding secondhand smoke is also crucial for non-smokers.

Test your home for radon
If radon exposure is suspected, using a home radon testing kit can help identify elevated levels. If levels are high, mitigation systems can significantly reduce radon concentration indoors.

Avoid workplace carcinogens
Follow safety guidelines and use protective equipment to minimize exposure to harmful substances at work, especially in high-risk industries.

Adopt healthy lifestyle habits
Regular physical activity has been shown to lower the risk of lung cancer and many other cancers. A diet rich in fiber, fruits, and vegetables may also provide protective benefits, as certain plant-based nutrients help support overall lung and immune health.

Early screening
Traditional chest X-rays are not effective for detecting early-stage lung cancer. However, low-dose CT scans have been shown to reduce lung cancer mortality by about 20% in high-risk individuals, particularly long-term smokers.