Emphysema is caused by prolonged exposure to smoke, fumes and air pollution, says the Mayo Clinic. People who smoke are the most likely to develop emphysema. In rare cases, a congenital condition involving a protein deficiency causes alpha-1-antitrypsin deficiency emphysema.
Smoking cigarettes is the leading cause of emphysema, but pipe and cigar smokers are also at risk, notes the Mayo Clinic. Smoking marijuana can also lead to emphysema. Exposure to any kind of secondhand smoke increases a person's risk of emphysema. Breathing chemical fumes and airborne dust from wood, cotton, mining and grain products makes people more prone to emphysema. Other risk factors include indoor and outdoor air pollution from sources such as heating fuel vapors and vehicle exhaust.
Emphysema is a gradual degeneration of lung tissue which makes breathing more difficult, explains WebMD. It is unknown exactly how smoking destroys the linings in the lungs, but smokers develop emphysema at a much higher rate than the general population. Air pockets develop and the lungs slowly get bigger, so exhaling becomes much harder. Emphysema and chronic bronchitis are conditions known as chronic obstructive pulmonary disease. There is no cure for emphysema, but for people who smoke, quitting slows the progression of the disease.