Yup and that's the first things doctors suspect, so x-rays and ECG, then stress tests, then camera up the groin all to find no problem. Next guess is lymphoma relapse so blood tests, then they listen to me and send me to various specialists but by the time I get to see one it's passed. I've...
Spent many years doing just that and have never found the answer. Best the doctors can come up with are arthritis and Menier's disease which always seem to flare up at the same time.