how cigarettes affect the lungs
Lung cancer is the most common form of cancer caused by smoking. More than 80% of cases of lung cancer are due to smoking. Cigarette smoke contains many chemicals that interfere with the body's method of filtering air and cleaning out the lungs. The smoke irritates the lungs and leads to overproduction of mucus. It also paralyses the cilia-tiny hair-like structures that line the airways and clean out dust and dirt.