I have frequent light headed episodes, along with shallow breath. They started 1 to 2 years ago, infrequently, and lasted a few seconds. Of late, they are much more frequent and lasting up to hours. They don t seem to have any connection with my activity or inactivity at the time. Any ideas? I am a male, age 72, with no known heart problems other than a murmur that is untreated. Thanks very much, Dwight L. Mills