What is the life expectancy of a 74 year old male with severe copd?

Depends: There are many factors associated with this type of question. How long have you been diagnosed, exactly what is "severe"do you smoke, etc. It has been shown that COPD patients who use pulmonary rehabilitation do better than those who do not.

Hard to tell: Given copd, your life expectancy is not as good as if you did not have copd. There is a scale to help physicians predict survival on patients with copd. It is called the bode score. In order to be able to calculate your score, you will need a 6 minute walk, body mass index and lung functions.