Smoking tobacco has a number of effects on the lungs, including damage to lung tissue, an increased amount of mucus and decreased breathing capacity when compared to healthy lungs, according to the University of Pittsburgh Medical Center. Cigarette smoke irritates and inflames the lining of the lungs, causing coughing and restricting airflow. Mucus is thicker and lingers longer in the lungs of smokers, which can lead to coughing, restrict breathing and breed infection.
Cigarette smoke also accelerates the natural aging processes in the lungs. The chemicals in cigarette smoke increase the likelihood of cancerous cells developing in the lungs by up to 2,000 percent. Smoking impairs the immune system, and smokers are more likely to develop lung infections, such as the common cold and pneumonia, cautions the University of Pittsburgh Medical Center. These illnesses are more severe and more likely to be life-threatening for smokers than nonsmokers.
Cilia in the lung, which filter impurities, become slower, less effective and less numerous, notes the University of Pittsburgh Medical Center. Smoking can make it harder to treat symptoms of asthma, such as coughing, difficulty breathing and feelings of tightness in the chest.
Quitting smoking can reverse a number of these negative effects, states the University of Pittsburgh Medical Center. Breathing can improve in as little as 72 hours and many related symptoms, such as wheezing, coughing and excess mucus, begin to decrease within a month. The risk of cancer decreases after five years and continues to decline as long as the ex-smoker abstains.