I am a 77 year old male, caucasian, non smoker, no drugs or alcohol. Two weeks ago I Walked 5 miles in 1:45 minutes, twice. This week playing golf and continuing when I exert myself I get physical pain in my lungs like thousand of pins. I become short of breath, increased heart rate, and slight uneasyness. This happens continues when I exert myself, like walking faster, but not rapidly. When I slow down it goes away in a short time. At resting and slow walking g it does not get activated. It feels l8ke my oxegen absorption is being blocked. Wally