What is the main cause of lung cancer?

The primary cause of lung cancer is smoking. Numerous studies have established a strong correlation between tobacco use and the development of lung cancer, making it the most significant risk factor. When individuals smoke, they inhale a mixture of more than 7,000 chemicals, many of which are known to be carcinogenic, meaning they can lead to cancer development. Tobacco smoke damages the cells lining the lungs, which can result in mutations that contribute to cancerous growth.

Although other factors like exposure to pesticides, high altitude living, and certain viral infections can have health impacts, they are not as strongly linked to lung cancer as smoking is. High altitude living primarily affects oxygen availability, while viral infections may influence other types of cancer but do not have a significant association with lung cancer specifically. This makes smoking the most predominant and well-documented cause of lung cancer, underscoring its critical role in the disease's etiology.