Jim I am in the same boat at the moment. The tests results I have had done to date came back last week as NAD (no abnormalities detected).

However that doesn't mean that what I am experiencing is psychosomatic (ie. all in my mind) it means that they either haven't done the right tests for the particular problem (ie. haven't looked hard enough) or medical science yet doesn't know everything and hasn't 'discovered' some causes for PN.

There are quite an extensive number of tests which can be done and sometimes it's a matter of exclusion.