Sixty to 80 percent of people with mild-to-moderate stages of emphysema are alive after four years, but only 50 percent of those with severe emphysema experience the same life expectancy, according to WebMD. People who exhibit the worst symptoms, such as weight loss and weakness, experience the shortest life expectancy.
Predicting life expectancy for individual emphysema sufferers is impossible because the disease varies so greatly among people, even those at the same stage, explains WebMD. Staging helps rate the progression and severity of emphysema, but it cannot provide an individual prognosis. In the absence of large studies about emphysema life expectancy, no reliable statistics exist to reassure sufferers who seek realistic prognoses.