The average emphysema life expectancy is rarely more than four years beyond diagnosis. By the time emphysema is diagnosed, the disease usually has already advanced to a severe stage. Emphysema is often caused by smoking and is common among elderly men. Clinical tests will provide a somewhat accurate estimate for emphysema life expectancy, though the prognosis also depends on follow-up treatment. Such treatments do not cure emphysema, but rather relieve emphysema symptoms and extend life expectancy slightly.

An early diagnosis might help to lengthen the average emphysema life expectancy. Even when diagnosed early, however, survival far beyond four years after diagnosis is generally not common. The disease is diagnosed at four different stages of development, i.e., stage one, two, three, and four. These numbers refer to "mild," "moderate," "severe," and "very severe," respectively.

In most cases, significant damage has already been sustained at the time of diagnosis, which shortens emphysema life expectancy. Those who smoke are at the highest risk of developing the disease, as are those who have a very low body weight. Elderly men are also found to develop the disease more often than other demographic groups. Those who fit into these categories and experience considerable coughing, excess phlegm production, and difficulty breathing are encouraged to see a doctor for a checkup. Once the disease develops into symptoms such as severe fatigue and intolerance to physical activity, it may have advanced to one of the severe stages.

An accurate estimate for emphysema life expectancy can only be determined with the use of a spirometer. This device calculates the amount of air a patient can exhale per second. Those with emphysema are usually only capable of exhaling less than half the amount of air of a normal, healthy person. When a drastically low reading is attained, life expectancy is estimated at four years or less.

A full four-year prognosis is actually considered a somewhat optimistic average, however. Emphysema life expectancy depends on not only the time of diagnosis, but the follow-up treatment a patient undergoes. In many cases, if untreated, a patient will only survive for about two years.

The most important treatment for many emphysema sufferers may be to stop smoking. Keeping away from secondhand smoke can also help. Sometimes emphysema is caused by a lung infection rather than from smoking. In such cases, medication is available which may slightly increase emphysema life expectancy and improve quality of life. Though these treatment may provide some relief, emphysema is said to be incurable.