Emphysema is a lung disease that typically develops after a long period of irritation and attack (usually from smoke or fumes). Cigarette smoking is the primary cause of this condition, but long-term exposure to air pollution can cause it, too. Common symptoms of emphysema include coughing, wheezing, and chronic mucus production. Treatment options vary, but often include medications, oxygen therapy, or surgery. The most important part of treatment, however, is to stop smoking if this is the primary cause.