In 1964, the U.S. Surgeon General announced that smoking has irrefutable harmful effects on health. MedlinePlus reports that smoking harms nearly every organ in the body, and is associated with multiple health problems. Besides lung disease, smoking can cause heart and blood vessel disease, stroke and cataracts, and harm a fetus during pregnancy. Smoking has a few different effects on the lungs.
Lung Cancer
According to MedlinePlus, cigarette smoking causes 87 percent of lung cancer deaths. The Centers for Disease Control and Prevention (CDC) estimate that smoking is responsible for about one in five deaths per year, including deaths from lung cancer.
The American Cancer Society (ACS) report that about 10 to 15 percent of lung cancers are of a type called small cell lung cancer (SCLC). Cigarette smoking almost exclusively causes SCLC, and it is very rare for someone who does not smoke to contract this type of lung cancer. This is also the most severe type of lung cancer, as the cancer cells multiply quickly, and often spread rapidly throughout the body, causing it to be difficult to treat.
Lower Respiratory Diseases
The CDC also reports that lower respiratory diseases such as chronic obstructive pulmonary disease (COPD, which includes emphysema and chronic bronchitis) is the fourth leading cause of death in the United States. The Surgeon General in 2004 remarked that smoking causes 90 percent of deaths. Smoking damages the elastic fibers of the air sacs in the lungs, preventing them from collapsing and expanding normally. Without these normal movements, a person cannot inhale or exhale efficiently. The body's tissues then do not get an adequate amount of oxygen. Though medications are available for the treatment of emphysema, there is no cure.
Lung Infections
The Surgeon General also remarked in his 2004 report that smokers have an increased incidence of lung infections. Lung infections in smokers tend to be more severe, and smokers have a harder time clearing the infections. The National Institute on Drug Abuse (NIDA) also reports on the link between smoking and lung infections. According to NIDA, smoking tobacco causes injury to the cilia that line the lung. These cilia are hair-like projections that line the lung and are important for clearing the lungs of mucus and microbes. When smoking damages the cilia, the lung is less able to clear out infectious agents.
